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Email Failure Reasons

Find out why your emails are really failing!

{person_name} is blocked.
The current company for {person_name} is blocked.


Recipient had no valid email address. -> Person with no emails for selected email priorities in settings or person has no emails at all


no valid "TO" address found -> Bounced email or BriteVerify validation failed for email

The expected flow for this is:
- send an email to 1000 people
- if many of these people have invalid emails, this sending email address might be marked as spam, so they won't be able to send any emails anymore
- so instead, we only send to emails we think are legit
- we then indicate which were not sent, and if user is confident that the email address is legit, they can try re-sending.


Bounced -> Bounced for mailgun


Invalid Recipient -> Bounced for gmail accounts


Unknown error on recipient's side -> This one, we should see which type of error is flagged


Already sent this stage to recipient.


failedPrecondition: Mail service not enabled -> For google accounts


Error encountered while sending using Gmail API -> For Gmail accounts synced through Nylas (shouldn't be many)


Invalid Recipient = 13 Means the email couldn't be delivered and was bounced.

No useable credentials. Please reauthenticate. If the issue persists, please contact support = 64 Likely needs to re-authenticate

Recipient had no valid email address = 3 People emails fail validation

This action can't be performed because the account's credentials are out of date. Please reauthenticate and try again = 15 Likely needs to re-authenticate

connection refused This means that the service we use to send emails was unable to connect to the user's email client. Usually due to sending in high volumes and is temporary.

Not delivering to a previously bounced address means that Mailgun has sent an email to this address before and it bounced, so they're not even going to try again

No MX for *email* means that the domain doesn't have an MX record so we can't send mail to it (probably misspelled email)

Sorry, no mailbox here by that name means that the recipient's email server couldn't find a matching email address

Envelope blocked usually means that the sender has been blocked by the recipient

Sorry, message looks like SPAM to me seems to mean that this message was caught by the recipient's spam filter

Recipient address rejected: Access denied means the recipient's email rejected the message, maybe due to spam filters

The email account that you tried to reach is disabled means the email account they were sending to is disabled

5.1.1 User Unknown seems to mean that the recipient's mail provider can't find a matching email in their domain

Complained The email recipient clicked on the spam complaint button and the recipient's email server provides feedback loops to Mailgun for these complaints.

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