What does tempfail mean in Gmail, and why is it happening?
Summary
What email marketers say11Marketer opinions
Email marketer from Email on Acid explains that a soft bounce, potentially indicated by a tempfail, can be triggered by factors like a full mailbox, a server being down, or the email content triggering spam filters. They recommend reviewing your sender reputation and email content.
Email marketer from SendPulse shares that a temporary failure can occur due to IP address related issues, for example being on a blocklist, or the IP not having enough of a 'warm-up' period.
Email marketer from Stack Overflow explains that temporary SMTP errors (4xx codes) indicate that the server is currently unable to process the request, but this condition is expected to be temporary. It could be due to resource limitations or maintenance.
Marketer from Email Geeks explains that it is only 0.1% so probably nothing to worry about. But check your delivery stats to see whether it was replicated/worse at other ISPs and check your open rates too… if Gmail open rates are significantly lower than other ISPs it could indicate that they’re also sending the email to Junk.
Email marketer from Reddit provides insight on the need to monitor blocklists. It explains how this action can allow for a temporary failure, and should be monitored to stop this happening.
Marketer from Email Geeks explains that it means the amount of rejections from Gmail side with a listed reason and something they catch in your traffic.
Email marketer from Sender explains that a low sender reputation can lead to temporary rejections or tempfails. Gmail may throttle or temporarily block emails from senders with a poor reputation to protect its users from spam.
Email marketer from Web Hosting Talk mentions that temporary failures can occur if the sending server lacks a proper reverse DNS (rDNS) record. Gmail and other providers use rDNS to verify the legitimacy of the sending server.
Marketer from Email Geeks explains that the reason is “Suspected Spam” and sounds like the email has been blocked / soft-bounced with a reason suggesting that something about your email, or the profile of your sending is spam-like. Consider your audience, list acquisition and hygiene, and the email's content to determine why Gmail might think it's spam.
Email marketer from Neil Patel Blog shares that soft bounces, which a tempfail could represent, can occur due to a full inbox, server downtime, or the email exceeding size limits. These are usually temporary issues.
Email marketer from Reddit shares that tempfails can sometimes be linked to email authentication issues (SPF, DKIM, DMARC). If your SPF record is misconfigured or missing, Gmail might temporarily reject your emails as a precaution.
What the experts say2Expert opinions
Expert from Word to the Wise responds that a common cause of tempfails is greylisting, where the receiving server temporarily rejects an email from an unknown sender to verify its legitimacy. Legitimate servers will retry sending the email.
Expert from Spam Resource explains that Gmail may use greylisting or throttling, causing temporary failures. This involves temporarily rejecting emails from unknown senders to combat spam.
What the documentation says4Technical articles
Documentation from Microsoft Support provides insight into delayed and bounced emails. It suggests a possible cause of temporary failure is that the message is too large.
Documentation from Mailjet explains that a temporary failure (tempfail) signifies that the message could not be delivered due to a transient issue. Mail servers will typically retry delivery for these messages over a certain period.
Documentation from Google Workspace Admin Help explains that a 'tempfail' usually indicates a temporary problem at the receiving end (Gmail in this case). It could be due to a full mailbox, a temporary server issue, or the recipient server being temporarily unavailable.
Documentation from RFC Editor defines temporary failures (4xx SMTP codes) as situations where the message could not be delivered but delivery might be possible in the future. Reasons include server overload, connection problems, or temporary unavailability of resources.