Log In

IP reputation represents just one piece of your delivery strategy. When email began, all we needed for good deliverability rates was a good IP reputation, nothing else mattered! Scarily enough, some email senders still believe this to be true. Well, far from it! So what are the other pieces to our puzzle?

What makes up a delivery strategy?

Domain reputation

Your domain’s reputation is extremely important. If your domain appears on a blacklist, this could have a detrimental effect on inbox placement, and the damage may even be irreversible. The components below and, of course, NEVER using a purchased mailing list should hopefully keep your domain blacklist-free. Unsure if your domain is on a blacklist? Use MX-toolbox and SenderScore to check now!

Domain authentication

It’s super important to ensure your domain is fully authorized and has the correct authentication records in place, such as SPF, DKIM, and DMARC. At SMTP2GO, we use VERP -Variable Envelope Return Path/automatic SPF. These records tell the incoming server who has permission to send on your domain’s behalf. Without the correct authentication in place, your emails could be seen as spoofing. 


If your content is spam-like, for example, includes too many links/broken links, has an undesirable ratio of images to text, includes HTML without a plain-text version, includes images without alt-text, no unsubscribe link, or has a low readability score, this could start triggering your emails to land in the spam folder.

We often recommend using a free service like mail-tester.com to check your emails before sending. Your score should be 9/10 at least! If you are an SMTP2GO user on a higher-volume plan (100K+), you can use the email testing tool found directly within your SMTP2GO account.


In order to determine which emails are accepted by recipient servers, mailbox providers follow RFC protocol on email formatting and content. In the last number of years, in order to crack down on spam, providers have become stricter in their email screening. Formatting errors include exceeding the maximum line length, missing header fields (date and message ID), or exceeding email address size limits. Please see the blog “Is Email Formatting Affecting Your Inbox Delivery?” for further details on RFC protocol.

Danger words

There are a number of words out there that spam filters are on the lookout for (especially when used in a subject line). See this infographic on danger words and phrases for the most common examples.


Believe it or not, email engagement has a huge effect on your overall sender reputation and should be a part of your delivery strategy. If your recipients are not engaging with your emails (opens, clicks, responses), they may be detected as unsolicited, and incoming servers may start to filter your emails into the spam folder. That’s why the next piece of our puzzle is extremely important.

List hygiene

And last, but by no means least, list hygiene! First of all, you need to use genuine list-collection methods to build your list, and NEVER purchase a mailing list. But once your list has started to grow, your job is not done! You need to keep on top of hard bounces, spam complaints, and unsubscribed recipients by removing them immediately from your mailing list. You should also remove disengaged recipients every 6 months to one year. This will ensure that your engagement rates stay top tip and your bounce and spam percentages remain low (there’s no point upping that score by sending further emails to the SAME bounced/spam recipients), meaning your emails will continue to keep smashing the inbox, as they should be.

Leave a Reply

Your email address will not be published. Required fields are marked *

Ready for better email delivery?

Try SMTP2GO free for as long as you like:

Try SMTP2GO Free → Paid plans available for over 1,000 emails/month.

Ready for better email delivery?
Try SMTP2GO free for as long as you like:

Try SMTP2GO Free See Pricing