Email Suddenly Rejected By Google Mail

[HappyWorld]

Suddenly all emails from my board have been rejected by gmail with this message :

Gmail has detected that this message is likely unsolicited mail. To reduce the amount of spam sent to Gmail, this message has been blocked. For more information, go to https://support.google.com/mail/?p=UnsolicitedMessageError

In xenforo mail options, i use "PHP built-in mail system" as "Email transport method"

DKIM etc are set up.
The only problems i have in Google Postmaster Tool :

1. Needs work — Set up TLS encryption
2. No PTR record.

When i check my server / domain on blacklist check, both are not blacklisted.

Sending email to other than gmail is fine.

Anyone has same issue?

 

[Mr Lucky]

It could be the up is blacklisted, especially if shared hosting.

This happens quite a lot and the best solution seems to be to use a smtp provided er rather than built in php mail.

 

[chillibear]

Sending email from an IP without a PTR record is generally a major red flag for receiving mail servers. I'm surprised it's been working until now to be honest. Odds are you may have to speak to your provider about the PTR records as I'm guessing you don't own the IP range yourself. Still that shouldn't be hard for them to do - unless the IP is shared between multiple clients.

As Mr Lucky has already said generally you'd be better off passing the job to a dedicated mail server rather than using whatever the mail command is using under the hood to send directly from your server.

 

[Wildcat Media]

It could be the up is blacklisted, especially if shared hosting.

Yep. One of the hosts I use unfortunately has a reputation due to scammers/spammers in the past signing up for throwaway sites on the host's servers, so most email admins just blacklist the entire hosting company. I don't like it either, but that's one of the risks these days.