On my site (developed with ASP.NET, if that matters) I have a support form, which is nothing more than three fields (i.e., name, email, and message) plus a Send button.

The form code generates emails from provided user input and sends them to: [email protected]. The form uses this address to send the messages: [email protected]. All the email for mysite.com is handled by Google Apps for Business.

The problem is: Google recently started marking emails sent from [email protected] as spam:

Delivery to the following recipient failed permanently:

     [email protected]

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain mysite.com by aspmx.l.google.com. [].

The error that the other server returned was:
550-5.7.1 [ip-address-was-here       7] Our system has detected that this message is
550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to Gmail,
550-5.7.1 this message has been blocked. Please visit
550-5.7.1 http://support.google.com/mail/bin/answer.py?hl=en&answer=188131 for
550 5.7.1 more information. sz7si15854448pab.203 - gsmtp

Obviously, visitors on my site can put spam messages in my support form. Anyway, I would prefer that these messages to end up in my Spam folder (or better the Inbox!) of [email protected].

So, what can I do to prevent Google from blocking [email protected]?

Shall I use a 3rd-party service for the support form? Or shall I tweak my site / form code somehow?

My site is on shared hosting if that matters.

2 Answers 2


Based on the SMTP transaction, the email servers for Gmail (used for Google Apps for Business) responded back that the IP address for your shared host's mail server is likely associated with unsolicited mail:

[ip-address-was-here 7] Our system has detected that this message is likely unsolicited mail. To reduce the amount of spam sent to Gmail, this message has been blocked.

You can report this to your shared hosting provider and request that they either attempt to remove their IP address from Gmail's filter list and other DNS Blacklists (not likely a quick fix), or switch you to a server with a different IP address that isn't listed in these or blocked by Gmail.

Alternatively, you can use a mail form provided by a third-party. Tweaking your form code however isn't going to fix this issue.


It may be because the email is seen as mass email, and has no unsubscribe button or acknowledgement of where it comes from (company name etc).

Third-party emailers can help your emails to be trusted more often.

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.