Email Warm Up Guide: 20+ Tips for Better Deliverability (2025)

Starting with a fresh email account can be risky. Statistics reveal that around 55% of emails might not reach the intended inbox but instead get flagged as spam. Warming up an email account is a crucial step to avoid this pitfall. It’s about gradually establishing trust with email providers by responsibly increasing your sending volume.

This process ensures your messages are received as intended, not sidelined as unwanted spam. This comprehensive guide will walk you through everything you need to know about email warm-up, from manual techniques to automated tools, ensuring your communications are both seen and heard.

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Main Takeaways

• Email warm-up improves deliverability by building your sender reputation with email service providers
• Google banned automated email warm-up services in early 2023, making manual warm-up essential for Gmail accounts
• The warm-up process typically takes 8 to 12 weeks to reach optimal deliverability
• Start with low sending volumes and gradually increase as you build domain reputation
• Proper authentication (SPF, DKIM, DMARC) is essential before beginning the warm-up process
• Want to skip the technical hassle? Our DFY service handles everything from warm-up to lead generation

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What Is Email Warm Up?

Email warm-up is the process of gradually increasing the volume of emails sent from a new or dormant email account to establish a positive sender reputation with Internet Service Providers (ISPs) and email service providers (ESPs). Think of it like training for a marathon—you start slowly and build up your endurance over time.

When you start with a small number of emails and progressively increase the volume, you signal to email providers that you’re a legitimate sender, not a spammer. This gradual approach helps avoid spam filters and ensures your emails land in the primary inbox rather than the spam folder.

Email warm-up applies to both new domains and existing domains that haven’t been used for email sending in a while. The process involves sending emails, receiving replies, and generating positive engagement signals that demonstrate your emails have value to recipients.

Why Email Warm Up Matters for Deliverability

Email warm-up is critical for several key reasons that directly impact your email marketing success and cold outreach campaigns.

Establishes Sender Reputation

Your sender reputation is like a credit score for your email domain. Email providers use this reputation to determine whether your messages should reach the inbox or be filtered as spam. A new email account has no reputation, which makes providers suspicious. The warm-up process builds this reputation gradually, proving you’re a trustworthy sender.

Prevents Spam Folder Placement

Without proper warm-up, your emails are significantly more likely to land in spam folders. This is especially true for new domains or accounts that suddenly start sending large volumes of email. The gradual increase in sending volume during warm-up helps you avoid triggering spam filters.

Increases Email Deliverability Rates

A well-executed warm-up process dramatically improves your email deliverability. By building trust with ESPs, you ensure more of your messages reach their intended recipients. This translates directly to better campaign performance and higher ROI on your email marketing efforts.

Avoids Account Restrictions

Many email providers have strict sending limits, especially for new accounts. If you exceed these limits or trigger spam filters, your account can be temporarily or permanently blocked. Email warm-up helps you stay within safe sending limits while gradually increasing your capacity.

Builds Long-Term Email Infrastructure

Email warm-up isn’t just about the first few weeks—it’s about establishing a sustainable email sending infrastructure. A properly warmed account maintains better deliverability over time, giving you a solid foundation for all future email campaigns.

How to Manually Warm Up an Email Account

Manual email warm-up is the most reliable and Google-approved method for Gmail accounts. While it requires more effort than automated solutions, it provides complete control and avoids the risk of penalties from email providers.

1. Set Up Email Authentication

Before sending any emails, configure these essential authentication protocols:

SPF (Sender Policy Framework): Verifies that your email comes from an authorized server. Add an SPF record to your domain’s DNS settings listing all servers authorized to send email on your behalf. Learn more about SPF records from Cloudflare.

DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails that proves they haven’t been altered in transit. Configure DKIM signing through your email provider or hosting service.

DMARC (Domain-based Message Authentication): Tells receiving servers how to handle emails that fail SPF or DKIM checks. Start with a monitoring policy (p=none) and gradually move to quarantine or reject as your reputation improves. Learn more at DMARC.org proves.

Using a custom domain instead of a generic email provider adds professionalism and credibility to your emails.

2. Start with a Small, Engaged Audience

Begin by sending 10-20 personalized emails per day to people you know—friends, family, colleagues, or existing business contacts. These should be people likely to open your emails and respond. The key is genuine engagement, not volume.

Craft each email to be unique and relevant to the recipient. Avoid using templates at this stage. The goal is to generate authentic conversations that signal to email providers that your messages have value.

3. Generate Genuine Two-Way Conversations

The most important factor in email warm-up is engagement. When recipients open your emails, reply to them, and mark them as important, it sends powerful positive signals to email providers.

Respond promptly to any replies you receive and keep conversations going. Consider subscribing to relevant newsletters and engaging with them by replying or clicking links. This reciprocal interaction further establishes your account’s legitimacy.

4. Gradually Increase Sending Volume

Follow a structured schedule to increase your daily email volume:

• Week 1: 10-20 emails per day
• Week 2: 20-40 emails per day
• Week 3: 40-80 emails per day
• Week 4: 80-150 emails per day
• Week 5-8: Continue increasing by 50-100 emails per week
• Week 8-12: Reach your target sending volume

Adjust this schedule based on your engagement rates. If you notice deliverability issues, slow down the ramp-up. The key is consistency and gradual growth.

5. Monitor Deliverability Metrics

Track these key metrics throughout the warm-up process:

• Inbox placement rate: Percentage of emails landing in the primary inbox
• Open rate: Percentage of recipients opening your emails
• Reply rate: Percentage of recipients responding
• Bounce rate: Percentage of emails that couldn’t be delivered
• Spam complaint rate: Percentage of recipients marking emails as spam

If you see concerning trends—high bounce rates, low open rates, or increased spam complaints—pause and reassess your approach. You may need to improve your email content, clean your list, or slow down your sending increase.

6. Maintain Consistent Sending Patterns

Email providers look for consistent, predictable sending behavior. Try to send emails at similar times each day and maintain a relatively steady volume. Sudden spikes or long periods of inactivity can hurt your sender reputation.

Not sure you have the time or resources to manage a proper warm-up? Our DFY email outreach service handles the entire process for you, from initial setup through campaign execution, so you can start generating leads without the technical complexity.

Automated Email Warm Up Services

In January 2023, Google implemented significant policy changes that banned automated email warm-up services for Gmail accounts. Google’s machine learning algorithms can now detect and penalize accounts using automated warm-up tactics.

The Google Ban on Automated Warm Up

Google’s security systems identified that automated warm-up services were generating artificial engagement signals that didn’t represent real user behavior. As a result, Gmail accounts using these services risked penalties including reduced deliverability, account warnings, or complete suspension. Review Google’s official email sending guidelines for best practices.

This means automated warm-up tools are no longer viable for Gmail accounts and should be avoided if you’re using Google Workspace or free Gmail addresses.

When Automated Warm Up Still Works

Automated email warm-up services remain effective for non-Google email providers, including:

• Outlook/Office 365
• Yahoo Mail
• Zoho Mail
• Custom SMTP servers
• Other email service providers

If you’re using these platforms, automated warm-up can save significant time while still building your sender reputation effectively.

Best Email Warm Up Tools for 2025

If you’re using non-Google email accounts or need assistance with the warm-up process, here are the top services available:

For Gmail Accounts: Proven Concept

Proven Concept is the best option for Gmail users because they use manual warm-up techniques that comply with Google’s policies. They provide comprehensive services including domain setup, email warm-up, and full cold email campaign management. Their manual approach ensures your Gmail account won’t be flagged or penalized.

For Other Email Providers

Several automated services work well for non-Gmail accounts:

Smartlead.ai ($39/month) – Offers unlimited inbox warm-up with advanced features for managing multiple accounts. Includes AI-powered engagement simulation and detailed analytics.

Warm Up Your Email ($29/month per inbox) – High-quality service with realistic engagement patterns and comprehensive reporting on warm-up progress.

Mailflow.io Auto Warmer (Free) – Basic automated warm-up for users on a tight budget. Good starting point for testing warm-up benefits.

Saleshandy ($34/month for unlimited inboxes) – Affordable option with solid warm-up capabilities integrated into a broader email outreach platform.

Warmup Inbox (Pricing varies) – Automated sequences with IP rotation and reputation monitoring to simulate real user interactions.

MailReach (Pricing varies) – Large network of warm-up inboxes with machine learning optimization for deliverability.

Reply.io ($29/month) – Cold email tool with integrated warm-up functionality, good for unified email campaign management. Check out Reply.io and their AI-SDR Jason.

Warmy.io (Pricing varies) – Advanced warm-up tool with AI-powered inbox rotation and detailed deliverability analytics. Try Warmy.io for automated warm-up with real-time monitoring.

Mailwarm (Pricing varies) – Specialized warm-up service focusing on gradual reputation building with customizable sending schedules. Check out Mailwarm for a simple, effective warm-up solution.

Email Warm Up Best Practices and Strategies

Beyond the basic warm-up process, implementing these strategies will maximize your success and protect your sender reputation.

1. Lead with Value, Not Requests

In your initial warm-up emails, focus on offering value without asking for anything in return. Share helpful information, resources, or insights relevant to your recipients. This approach builds goodwill and increases the likelihood of positive engagement.

2. Establish Credibility Early

Briefly introduce yourself and highlight your relevant experience or credentials. This helps recipients understand why they should pay attention to your emails and builds trust from the first interaction.

3. Craft Compelling Email Content

Even during warm-up, your emails should be well-written and engaging. Use clear subject lines, personalized greetings, and concise messaging. The better your content, the more engagement you’ll generate, which accelerates the warm-up process.

4. Provide Clear Context

Always give recipients a reason for your email. Whether you’re following up on a previous conversation, sharing relevant information, or making an introduction, clear context makes your email feel legitimate and purposeful.

5. Segment Your Audience

Not all recipients are created equal. Segment your email list based on engagement levels, industry, or other relevant factors. This allows you to tailor your warm-up strategy and content to different audience groups.

6. Clean Your Email Lists Regularly

Remove invalid email addresses, hard bounces, and unengaged recipients from your lists. High bounce rates and low engagement hurt your sender reputation. Use email verification tools to maintain list quality.

7. Test Different Email Elements

Experiment with subject lines, sending times, email length, and content formats during your warm-up. Track which variations generate the best engagement and refine your approach accordingly.

8. Respect Unsubscribe Requests

Always honor opt-out requests immediately. Including a clear unsubscribe link and processing requests quickly demonstrates respect for recipients and helps maintain a positive sender reputation.

How Long Does Email Warm Up Take?

The ideal email warm-up duration typically ranges from 8 to 12 weeks for reaching optimal deliverability. However, several factors influence the exact timeline:

Factors Affecting Warm Up Duration

Domain Age and History: New domains with no sending history require the full 8-12 weeks. Older domains with established (but dormant) reputations may warm up faster, potentially in 2-4 weeks.

Target Sending Volume: If you plan to send high volumes (1,000+ emails per day), expect a longer warm-up period. Lower volume senders (100-300 per day) may complete warm-up faster.

Engagement Rates: Higher engagement (opens, replies) accelerates the warm-up process. If your emails generate strong positive signals, you can progress faster through the ramp-up schedule.

Email Service Provider: Different ESPs have varying requirements. Gmail and Outlook tend to be more stringent, while smaller providers may be more lenient.

Email Content Quality: Well-crafted, relevant emails that avoid spam triggers warm up faster than generic or promotional content.

Warm Up Is Ongoing

It’s important to understand that email warm-up isn’t a one-time process. Once you’ve completed the initial warm-up, you must maintain consistent sending patterns to preserve your reputation. Long breaks or sudden changes in sending behavior can require re-warming your account.

Think of warm-up as establishing a baseline, and ongoing maintenance as keeping that baseline strong. Even after the initial 8-12 weeks, continue monitoring your metrics and adjusting your strategy as needed.

Understanding Email Sending Limits

Email sending limits vary significantly across providers and directly impact your warm-up strategy. Exceeding these limits can result in account restrictions or deliverability issues.

Major Email Provider Limits

Gmail (Free): 500 emails per day via web interface, 100 per day via SMTP

Google Workspace: 2,000 emails per day (500 during trial period)

Outlook.com: 5,000 emails per day, 500 recipients per email

Office 365: 10,000 emails per day, 30 messages per minute

Yahoo Mail: 500 emails per day, 100 emails per hour

These limits apply to your warm-up strategy because you need to stay well below them during the initial phases. Start at 5-10% of your provider’s daily limit and gradually increase.

For detailed information about email sending limits across all major providers, see our comprehensive guide on email sending limits of various email service providers.

Staying Within Your Limits

Monitor your daily and hourly sending to ensure you’re not approaching provider limits. Build in buffer room—never send at exactly your maximum capacity. This gives you flexibility for important one-off communications and protects against accidental overages.

If you need to send higher volumes, consider using multiple email accounts or domains and distribute your sending across them. This strategy also provides redundancy if one account experiences issues.

How to Know Your Email Is Warmed Up

Several indicators tell you when your email account has successfully completed the warm-up process and is ready for full-scale campaigns.

1. Consistent Inbox Placement

The primary indicator is that your emails consistently land in the primary inbox, not spam or promotions folders. You can test this by sending to multiple email addresses you control across different providers (Gmail, Outlook, Yahoo) and checking placement.

2. Strong Engagement Metrics

Track these engagement benchmarks:

• Open rate: 20-30% or higher for cold emails, 30-50%+ for warm audiences
• Reply rate: 5-10%+ for cold outreach, 15-25%+ for existing contacts
• Bounce rate: Under 2% consistently
• Spam complaint rate: Under 0.1%

When you’re consistently hitting these numbers, your warm-up is working.

3. Positive Sender Reputation Scores

Use tools like Google Postmaster Tools, Microsoft SNDS, or third-party services like GlockApps to check your domain reputation and test email deliverability. Scores above 80 (on a 0-100 scale) indicate good sender reputation.

4. Successful Cold Email Responses

If you’re warming up for cold email campaigns, you’ll know you’re ready when test cold emails start generating positive responses. Send a small batch of cold emails (50-100) and measure the results. If you see reasonable open and reply rates, you’re ready to scale.

5. Stable Deliverability Over Time

True warm-up success means maintaining consistent deliverability day after day. If you can send at your target volume for 2-3 weeks straight with stable metrics, your account is fully warmed and your infrastructure is solid.

Common Email Warm Up Mistakes to Avoid

Many people sabotage their warm-up efforts through preventable mistakes. Avoid these common pitfalls:

Sending Too Much Too Soon

The biggest mistake is impatience. Jumping from 50 to 500 emails overnight will trigger spam filters and damage your reputation. Stick to gradual increases of 50-100 emails per week.

Buying Email Lists

Never use purchased email lists during warm-up (or ever, really). These lists contain outdated addresses, spam traps, and unengaged recipients that will crater your deliverability. Only email people who have opted in or have a legitimate connection to you.

Ignoring Engagement

Volume alone doesn’t warm up an account. You need genuine engagement—opens, replies, and positive interactions. Sending to unengaged recipients hurts more than it helps.

Poor Email Content

Even during warm-up, content quality matters. Emails full of spam triggers (excessive caps, multiple exclamation marks, suspicious links) will hurt your reputation regardless of sending volume.

Inconsistent Sending Patterns

Sending 200 emails one day, then nothing for three days, then 400 emails creates suspicious patterns. Maintain consistent daily sending throughout the warm-up process.

Skipping Authentication Setup

Failing to configure SPF, DKIM, and DMARC properly will result in poor deliverability regardless of warm-up efforts. These technical foundations must be in place before you start.

Stopping Warm Up Too Early

Don’t declare victory after two weeks and immediately send to your entire list. Complete the full 8-12 week warm-up process and gradually scale to your target volume.

Using Automated Tools with Gmail

As mentioned earlier, automated warm-up services are now banned for Gmail accounts. Using them will result in penalties, not better deliverability.

Email Warm Up FAQs

Start Warming Up Before Cold Emailing

Email warm-up is not optional for successful email campaigns—it’s a fundamental requirement for ensuring your messages reach their intended recipients. Whether you’re launching a cold email outreach campaign, starting email marketing for a new business, or reviving a dormant domain, proper warm-up is essential.

The investment of time and effort in warming up your email account pays significant dividends in the form of better deliverability, higher engagement rates, and ultimately, more successful email campaigns. Take the warm-up process seriously, follow best practices, and maintain consistent sending patterns for long-term success.

Remember that for Gmail accounts, manual warm-up is now the only safe option following Google’s ban on automated services. While this requires more hands-on effort, it ensures compliance with provider policies and builds genuine sender reputation.

If manual warm-up seems overwhelming or you’re using Gmail, consider hiring a service like Proven Concept that specializes in compliant, manual warm-up techniques. For other email providers, automated tools can significantly streamline the process while still delivering results.

Alternatively, if you want to skip the warm-up hassle entirely and focus on your business, consider our Done-For-You (DFY) email outreach service. We handle everything from domain setup and email warm-up to campaign execution and lead generation, so you can get results without the technical headaches.

The key takeaway is simple: never skip email warm-up. Your sender reputation, deliverability rates, and campaign success all depend on it. Start your warm-up process today and build the email infrastructure that will support your business growth for years to come.

References

• Email Deliverability Testing
• Google Bans Cold Email Warmup
• Manual vs Automated Email Warm-up
• 10 Tips to Keep Email Out of the Spam Folder
• Email Warm-Up Best Practices 2025
• Email Deliverability Guide
• Email Domain Reputation Guide
• DMARC, DKIM, and SPF Setup Guide
• Note: Some links in this article are affiliate links. We only recommend tools we’ve vetted and believe will help improve your email deliverability.