Just as you customize G Suite to handle incoming mail, some external recipients set up their email system to suit their needs. As a result, you might encounter issues with email you send to them.
Common issues and recommended action
- If the email was sent less than 30 days ago, you can use Email Log Search to trace the transit of your message to the recipient’s email system.
- For another way to discover a delay in email delivery, get a copy of the received message header and paste it into the G Suite header analysis tool. It shows whether the email was delayed in transit or after the recipient’s mail server accepted the message for delivery.
If a recipient server rejects an externally sent message transmitted by Google servers, Google provides a non-delivery report. This is sometimes called a "bounce message." It appears in the user’s inbox, stating that the message was bounced.
The bounce message usually includes the SMTP reply from the recipient server that provides a good indicator of why the server rejected it.
- Contact the recipient to advise them of the issue and suggest they whitelist your domain or email address.
- If you still need help, contact support.
Best practices for sending email
To reduce the risk of encountering some of the issues mentioned above, administrators should put the following practices into action.
If you’re sending out surveys, flyers, or other mass communications through G Suite or a third-party email system, follow the best practices outlined in Prevent mail to Gmail users from being blocked or sent to spam. This reduces the risk of your recipients’ mail systems marking your email as spam or blocking your domain.
You can use SMTP-relay if you:
- Set up a scanner, printer, or web app to send email (for example, scan to email).
- Use an additional non-Google, email-capable system (for example, CRM, ticketing, or marketing automation) to scan outgoing messages for spam.
By causing non-Google email to appear to come from your G Suite domain, SMTP-relay results in the authentication of these emails.
Whitelisting means adding a domain to a list of approved senders. While at the recipient's discretion, whitelisting largely eliminates the risk of future email not arriving to them. You can do the same for them by adding their domain to the spam filter in G Suite.