If you encounter deliverability issues at a private domain (or your own domain), you might have to have your sending IP address and/or sending domain added to a list (i.e., an "allowlist") in order to ensure delivery. Private email domains (such as those owned by private companies and organizations) typically have more aggressive filtering in place than do the large, public email-service providers (such as Gmail and AOL).
It's important to note that being on an allowlist does not guarantee that email messages will be delivered. The allowlist is managed by the receiving email system. If the sender is on the allowlist, but is not following other deliverability best practices, their inclusion on the allowlist could be ignored and the email rejected.
Allowlisting at your own organization
When you use an external email server to send email on your behalf, you could see deliverability issues when receiving email at your organization. This is because your email server can identify email sent outside of its system (using your sending domain) as being "suspicious" and either quarantine it or flag it as spam. In order to prevent this, have your IT department allowlist your IP addresses prior to sending any messages through our system.
- Provide your IT department with the values of Assigned IP address and Return path, which can be found by navigating to Settings > Account Profile.
Allowlisting at other private domains
If your email messages are not being delivered to the contacts' inboxes at a private domain, contact the domain owner or postmaster to request that they allowlist your publish IP address and your "from" address.
Allowlisting instructions
Admins
Below are links to instructions for common spam filters.
- Mimecast - configure permitted senders
- Microsoft Exchange - create safe sender lists (applicable to Exchange Online Protection; Microsoft Defender for Office 365 plan 1 and plan 2; Microsoft 365 Defender)
Users
Below are instructions for common email clients.
Outlook
- Right-click a message in the preview pane (double-check the Junk and Clutter folders for messages too).
- Click the dropdown list and select Junk.
- Select Never Block Sender's Domain.
NOTE: If the message was found in the Junk or Clutter folder, you can move it to the inbox.
Gmail
- Click the Gmail dropdown list (on the left side of the screen) and select Contacts.
- Add the "from" address to your contact list.
If the message was found in the spam folder, right click it and select Not Spam. Additionally, you can move messages to their proper classification folder, if needed.
AOL
Right click a message and select Add to Contacts. Alternatively, select Contacts on the left sidebar and add the sender's "from" address. If the message was found in the spam folder, right-click it and select Not Spam.
Yahoo
- Click the Contacts icon (in the upper left corner) and select New Contact.
- Add the sender's email address.
If the message was found in the spam folder, right click it and select Not Spam. if you see the address in the block list, select the address you wish to remove and click Remove.
Other email clients
Add the sender's "from" address to your contact list/address book. If the message was found in the spam folder, move it to the inbox or right click it and select Not Spam.