I am sending an email to a maximum of 14 gmail users. They are part of a small group of paid subscribers. In a send to all 14 1 or 2 are normally returned saying

Reason: Remote host said: 550 5.7.1 RFC 2822 specifications for more information

It is not an email to the same member each time and seems random. Has anyone ever expereinced this before?

  • How do you send it? What's the tool?
    – initall
    Commented Feb 1, 2013 at 13:52
  • The emails are coming from a webform. A user completes the web form to send the emails. The form gets the emails from a mysql database and then using a php script (authSendEmail) it send the mails. It goes through no problem to all domains bar gmail and then only has problems with roughly 1 in 9 email sends.
    – user22988
    Commented Feb 1, 2013 at 15:17

3 Answers 3


You're most likely not authorized to send e-mail from that system for the domain you're trying to use in the 'From' address per SPF. The webserver should use the domain's authorized mail server as a smart relay.

A lot of systems don't give useful error messages when they think you're a spammer, as it just tells the spammer what they need to fix to get their e-mails through.

There's a chance that the emails that look like they're going through are really being delivered to the recipients' spam folders, and the random fails are to give you a warning so in case it's something done in error you have a warning to correct the problem.

(and this would likely have been better to ask at Server Fault, being an SMTP question; I haven't had to administer an SMTP server in 9 years, so I know of SPF, but I've never had to deal with the issue that it causes)

  • I am one of the users on the list and my emails get through directly to my inbox. all the users have added the send email address to their contacts as well.
    – user22988
    Commented Feb 1, 2013 at 19:08
  • I have performed checks on sites like solvedns.com and have no warnings. There is a valid SPF record.
    – user22988
    Commented Feb 1, 2013 at 19:25

I sent an email from the standard web interface and then worked out it was the form. Looking in the code there were 2 lines causing errors

$headers .= "To: $nameto " . $newLine;

$headers .= "From: $namefrom " . $newLine;

As these were being added to the header they were being duplicated and gmail did not like it.


Everything I've seen about this error code says it indicates the receiving mail box was unavailable at the time. There could be many reasons for this from their server being down, to the mailbox being full/non-existent, to more esoteric things. Do you get the message more often for any particular recipients, and have you asked them if they've had downtime, etc?

Getting 550 5.7.1 apparently means that the message was rejected, due to the "submitter" (presumably your PHP script) not being authorized to send on behalf of the domain involved. There are no easy permalinks, but do an in-page search for "5.7.1" in RFC 4405 and RFC 4408. Another article I found says the message can indicate you being on a blacklist. While that's obviously not true since the messages do sometimes go through, it does suggest again that you're triggering some checking/spam mechanism, which would be consistent with the authorization concept in the RFCs. That should give you a bit more to work with for hunting this down.

But it seems like it might be time for you to go through support channels for the script you're using, unless it's some standard tool. I've never encountered that before.

  • The messages are all being sent to gmail users. They are not coming from gmail.
    – user22988
    Commented Feb 1, 2013 at 15:16
  • My comment above was misdirected; I thought you were sending from GMail. At any rate, though, the error code is coming from their server. I found a bit more about the specific message you're getting(5.7.1); added above.
    – Su'
    Commented Feb 1, 2013 at 16:01
  • what i don't then understand is why it sometimes work and other times doesn't. i send the exact same message to 3 recipients on 3 occasions. Twice it goes through and then on the third one email will be bounced. It is like they have a threshold of returning 1 in every 9 emails of this type.
    – user22988
    Commented Feb 1, 2013 at 16:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.