Overview of delivery issues
Why recipients in a mailing list may not receive emails sent from Certain or may not receive their registration confirmation emails:
- If an email server filters out a message as spam, the email is typically quarantined and does not reach the destination.
- One reason that spam filters block email addressed from an Application Service Provider (ASP), such as Certain, is that the "From" address is not using the same domain as the mail server.
- For example, if the "From" is eventplanner@example.com, the email still goes out with Certain's mail server's DNS host name (mail.certain.com) in the header.
To reduce the amount of email quarantined as spam, the default setting in Certain Platform is to modify all email sent from Certain servers so that the "From" address is always event_information@certain.com and the display name is that of the Registration Contact. The "Reply-To" address will also be that of the event's Registration Contact. The receiving mail server will recognize that the email's "From" address is in the same domain as the sending mail server.
Default content and sender behavior
The default setting in Certain Platform changes the FROM value to reduce quarantine risk. The Event FROM value can be set to the event registration contact in the FROM field by going to: Account Settings > Implementation > Security Settings > Set Email FROM value to "Use Event Registration Contact".
If you change this setting, review the information below and contact Certain Support to ensure you pass DMARC security checks.
The Email "Chain" – a filtering device
When you are logged into Certain and send an email update to hundreds of attendees, those emails pass through an email "transmission" chain. They pass through a series of mail servers and are subject to scrutiny at several levels:
- Certain sends these emails using SendGrid.
- Once SendGrid determines the emails are safe to send, their mail servers engage with the recipients' email servers (or an email appliance acting in lieu of those servers).
- This is where another key filtering occurs:
- In a B2B situation, rarely do you directly engage with the end point mail server. You will most likely deal with an appliance that scans for malware, checks for blacklisting, scans content, applies whitelisting settings, and eventually makes the determination to let the email through to the endpoint mail server (or not).
- In many B2B situations, you also face client-side filters, such as Outlook’s Junk folder, which has its own personalized criteria and threshold for keeping email out of the primary inbox.
- In a B2C situation, the top 5 ISPs cover about 80% of mailing addresses. ISPs have their own filtering systems with requirements that are different in the sense that they push back on massive amounts of SPAM, in the order of hundreds of billions of emails in a year.
Based on this quick breakdown, there are many opportunities for emails to:
- not be sent
- not be accepted
- be accepted but placed in the SPAM or JUNK folder
How to control deliverability
There are several aspects of your email communication that affect how emails are delivered. Some are technical and designed to authenticate the mail you send through Certain. For the rest, it is about best practices.
1. Identify yourself
SPF records and Domain Keys are tools designed to prove that emails sent through Certain are coming from a valid source. Since SendGrid uses an IP address different from the one tied to your domain, establishing this record will ensure mail servers take the incoming emails as legitimate. Please contact Certain Support to receive an updated SendGrid Authentication email. This email will include a list of records that need to be added to your DNS host and help improve deliverability by showing inbox providers that you own the domain.
2. Know your own environment
As you send test emails to yourself through Certain, you need to know whether your own mail server uses a SPAM firewall. If you do not get your test email, this is the first location to check, as SPAM firewalls are keeping track of the emails they bounce. Testing with a regular ISP email address is also a good idea, as it will establish a baseline of what another mail server accepts (or does not).
3. Follow best practices
There are many soft rules that apply to email communication best practices. With different email filters in place, insignificant mistakes, such as an email subject that is too long, may prevent delivery to a few mail servers while still allowing delivery to others. The rule is simple: If emails are delivered to some addresses and not others, it is related to your content and practices.
The Email chain – continued
When you are logged into Certain and sending an email update to hundreds of attendees, those emails pass through an email transmission chain. They pass through a series of mail servers and are subject to scrutiny at several levels:
- SendGrid is used to send these emails.
- After SendGrid determines the emails are safe to send, their mail servers engage with the recipients' mail servers (or email appliance acting in lieu of those servers).
- In a B2B situation, you will likely deal with an appliance that scans for malware, checks for blacklisting, scans content, applies whitelisting settings, and ultimately decides whether to let the email through to the endpoint mail server.
- In a B2C situation, major ISPs have their own filtering systems with requirements that differ and are designed to push back on massive SPAM.
- Opportunities for emails include not being sent, not being accepted, or being delivered but placed in SPAM/JUNK.
Related handling and notes
This article discusses delivery considerations and does not replace DMARC/ DKIM/ SPF configuration guidance. For further steps, contact Certain Support to ensure proper DMARC, DKIM, and SPF alignment.