Email Delivery

When an email is sent to a submitter or reviewer there is a chance that it will be marked as spam by automated filters. Spam filters assess a mixture of technical details (to do with how the email was sent, and who it was sent from), and the content of the emails.

We’ve taken several technical and content-related steps to improve the delivery rate of your emails, but there are also important things you need to consider when designing your email templates.

For example, speaker invitation emails may well be the first time a recipient receives an email from Lineup Ninja. In that email may be some text asking the recipient to click a link and submit personal information. There is a high risk of spam filters seeing this as an unsolicited phishing email. So, we recommend that you do some research and think carefully about the wording of such emails.

You can find an excellent guide on what spam filters look for when assessing emails and ways to avoid falling foul of them here. This guide really relates to email marketing campaigns, which are slightly different to the ’transactional’ emails that you’re sending from Lineup Ninja, but it still contains useful information on improving delivery rates.

Email Subject

The subject of an email is critically important for delivery, particularly to Office 365 users. For example, in testing we found ‘Your submission received’ would not be acceptable but ‘Thanks for your submission’ is fine. The default subjects we have provided were all tested successfully, if you change the subject we suggest you test your email (see below).

Email Content

The main body of the email is also important. Certain words and phrases make your emails look more like spam. See this list of spam trigger words to avoid in your templates.

Again, we recommend reading the guide mentioned above to understand more about how your content affects delivery rates.

If you embed header and footer images into your emails, this may affect their deliverability. Spam filters generally ’like’ a specific ratio of 80% of the email’s space being taken up by text, and only 20% taken up by images. You can check how your emails compare to this ratio by using a testing service like Mail Tester - see the testing section below.

Email Disclaimer

By default, we include a ‘Lineup Ninja’ disclaimer on all emails that are sent. This disclaimer serves two purposes:

  • Allows users to unsubscribe and informs them of the Lineup Ninja privacy policy
  • Makes the content of the email longer. This reduces the chance of the email being marked as spam

The disclaimer appears beneath any footer image you provide and in smaller text to the body to distinguish it from the body.

There is an option to toggle this disclaimer on or off as you wish and you can replace it with your own. If you toggle it off we strongly suggest you replace it with something of a similar length.

Testing Your Templates

The easiest way to test your templates is to just try them with your email address. Invite yourself to give a submission then process it through the Submission Stages.

We have found that Office 365 is the most picky service regarding marking email as Junk. You can test Office 365 by signing up for a free account at and then creating a submission with that email address.

You may also want to try a spam testing and reporting tool. We like Mail Tester - it’s user-friendly and gives you a detailed report of how your emails should perform. There are a few important things to note:

  • Mail Tester only checks the content against Spam Assassin’s database - other email services (Outlook, Google, Apple) will have their own spam words databases and algorithms for detecting spam. So, Mail Tester isn’t a substitute for testing emails to Office 365, Google etc. It just gives you more detail.
  • Mail Tester may give you a warning about a missing DMARC record: this is incorrect: Lineup Ninja’s DMARC record does actually work, but doesn’t show up in Mail Tester’s report for technical reasons (see “Technical Aspects” below). This doesn’t affect the overall score and you can disregard this warning.
  • Mail Tester may show a warning about a missing “unsubscribe header’. We have implemented unsubscribe in a very specific way due to other considerations around how to handle user accounts. This doesn’t affect the overall score and you can disregard this warning.
  • Mail Tester only gives you 3 free tests per day!

If you are struggling with testing your templates then please reach out to support.

Technical Aspects

There are several technical aspects to achieving successful email delivery. We have put in place the following:

  • Dedicated IP addresses - We don’t share our infrastructure with bulk email senders
  • SPF Records - A technical measure to ensure other people can’t send emails from
  • DKIM - A technical measure to ensure the content of your email cannot be changed by a 3rd party and to validate that it is being sent by Lineup Ninja.
  • DMARC Records - a policy that allows the sender to tell the recipient that the emails are protected by SPF / DKIM and give instructions for what the recipient should do if neither of them passes. Lineup Ninja has a DMARC policy in place for its top level domain ("”), and this policy cascades to subdomains (e.g. “”).

Next: Submission Stages

Still can’t find what you’re looking for? Email and one of the team will get back to you as soon as possible.​​​​​