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Home/Knowledge Base/Getting started with deliverability

Deliverability problems

Last Updated: Jul 9, 2025

Factors affecting email deliverability

Many factors are at play that determine whether or not your emails go into a recipient’s inbox or not.

The key ones include:

  • Sender reputation: This is one of the most significant factors impacting deliverability.  Your sending email address, domain and sending IP address should be free from any previous email abuse or spamming history;
  • Email content quality: Your email content should be relevant to the recipient and spam-free. E.g., excessive use of capital letters, inclusion of spam words, exclamation marks, and other spammy tactics are a strict no-no that may trigger spam filters;
  • List quality: You should only ever be sending to opted-in subscribers who’ve expressed interest in receiving your emails. Cleaning up inactive (dead) subscribers and using best practices like double opt-ins is a must;
  • Use of security mechanisms: When you set up secure emailing settings such as SPF and DKIM, it signals that you are a genuine business that is what it claims to be. You can learn more about DKIM/SPF records by clicking here.
  • Engagement: Your open, click-through, reply, unsubscribe and report spam rates are all closely monitored by ISPs to determine your audience’s experience. More opens, clicks and replies tell them that they are finding your content valuable, therefore, more chances of your emails getting delivered to inboxes;
  • Optimizations: Not optimizing your email for viewing over mobile or with popular email clients can result in lower engagement and poorer engagement metrics;
  • Internal firewall issues: Sometimes, especially with corporate and university filters, regular emails look suspicious and are blocked. Check the allow listing information (other providers refer to it as “whitelisting”). If that’s the case, you should alter inbox filtration settings and create an exception/whitelist sendersrv.com.
  • Others: spammy subject lines, sudden increase in sending frequency (or volume), excessive use of images and attachments, lack of segmentation, unclear unsubscribe links and more could also impact deliverability negatively.

That’s it!

If you got stuck on a specific task or can’t find a way to execute a particular job, contact our support team via LiveChat or [email protected] – we’re here to help 24/7.

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