Fix email deliverability for startups

3 min readJan 4, 2022

For a new company, email deliverability is a hard problem to solve. You buy a new domain, start sending out sales and transactional emails, and you will quickly realize the following issues.

  • Sales emails will have a low response rate. Much lower than the typical 2% benchmark.
  • App notification emails to customers bounce, automatically unsubscribed, spam filtered, and land in the wrong tab.
  • Your app-generated emails are landing in the promotion tab.

All because you have a null email reputation.

While these issues are solvable, it takes time to fix them. If you don’t start addressing it soon, your domain’s email reputation may get into a negative feedback loop. Since the open rate stays low, low reputation emails get sent to the spam, emails in the spam folder are discarded, the open rate gets lower every day and so on.

Here are a few tips on optimizing email deliverability by reducing the spam rate and increasing the chance of landing in the right tab.


Measure email deliverability

I used Sendgrid’s email testing to get a sense of our deliverability. We were already using Sendgrid for all transactional emails, so it was easy to do.

It’s hard to solve a problem you cannot measure. Inversely, if you are able to measure it, you can start fixing it.

  • Configure the DNS correctly. Here is a good guide
  • Separate the sales, marketing, transactional, and the main emails separate with different domains & IPs. So that your transactional emails for your customers are not affected by the cold sales outreach email.
  • Get a dedicated IP. Transactional email services like Sendgrid, put you on a shared IP by default. This means your neighbours’ good or bad email reputations will affect your email’s reputation. Take out that uncontrollable and random variable by moving to a dedicated IP. Then warm up the domain & IP together.
  • Only a fraction of sales and marketing emails receive an engagement. Offset the low engagement rate with positive engagement. Use an email warming service. I went with Folderly and saw good results.
After 3 days of use, we started to see some improvements. Further validated by Sendgrid tests.

Don’t act like a spammer.

  • Have less than three links in the emails if possible. Preferably, none.
  • Links should be short. A long link is a sign of spam.
  • Do not include Google Storage or S3 links.
  • Avoid HTML. HTML templates might land your emails in the promotion tab.
  • Do not attach files in the first cold outreach email.
  • Continuously analyze your outbound emails with tools like
  • Little to no text on images. Scammers use text on images to bypass spam filters.

Continuously monitor deliverability. If you see an issue, reduce the number of outbound until you correct it. Take the opportunity to learn what works and what does not work in your situation.

Updates Jan 9, 2022

Few more tips.

  • In the case of cold outreach emails, do not include links in the first letter. It can trigger the spam filter. Instead, add the links in the 3rd or the 4th letter.
  • Don’t do bulk sending. Have a few minutes of intervals between each send.
  • Scale the number of outreach bit by bit. Don’t start sending out hundreds of emails per day.




Software Developer Focused on Business Applications of A.I. Toronto, Canada Based.