One of the most common challenges for someone sending emails at scale is getting caught up in spam filters. The good news is… you are about to know most of what you need to avoid the dreaded spam folder.

There is one main thing you should know about how Gmail, Outlook, and other email providers look for spam:

They look for accounts that are not acting normal! 

To make sure your account continues acting normal, here are 6 things to keep in mind:

  1. Make sure your domain is healthy
    • If you are a Gmail user you can check your domain health here; for other email providers check domain health here
    • Use multiple subdomains to hedge the risk and keep your main domain healthy. For example, instead of sending cold emails with, I’d purchase and and send my cold emails using those domains. 
    • Once you buy a domain, it is important to warm it up. To do this you can either use an email warming tool or do it yourself by sending 20 emails one day and increasing by 1.5x each day (20, 30, 45, and so on). Check out mailwarm.
  2. Send emails to quality leads 
    • If the emails you are sending are constantly bouncing, email providers will raise a red flag. As long as your bounce rates are less than 3%, you should be good to go.
    • To verify email addresses before sending, look into a tool like this.
    • If you’re scraping emails on LinkedIn, be sure to verify emails before adding them to your mailing list.
  3. Don’t write spammy emails 
    • Write your cold emails as if you were reaching out to a friend. Really long, formulaic emails are easy to discover. You can check the quality of your email using this tool.
    • Including attachments, links, and tracking link clicks all jeopardize your email
  4. Throttle the number of emails sent each day
    • Best practices for a healthy domain indicate 300-500 emails per day depending on how similar or different they are. Sending more than this is not a great idea if all emails are identical.
    • more advanced mailing list systems have features in place to make sure you send the appropriate amount 
  5. Personalize emails 
    • The more you personalize your emails, the more natural they will look. People who send 50-100 really personalized emails per day rarely run into spam issues. However, if you are sending 300-500 per day where a portion is new cold emails, others are follow-ups, and the rest is a different copy there should be no problem. 

  6. Throttle the time in between emails
    • Most advanced mailing list management systems do this automatically. We space emails by about 15-20 seconds chosen at random. 

There is definitely no golden formula for this, but by being aware of best practices and using a tool that is built to put you in the best position to land in the inbox, you should be in the green!