I am on a Inmotion Hosting VPS server, with the latest install of PHPList and I am getting most of my emails with a failure of: SMTP Error: data not accepted.SMTP server error: DATA END command failed
Even though PHPList has this failure, the emails are being delivered multiple times.
It’s way too late to be helping you, but just FYI I just ran into this same problem on my installation.
Nothing has changed on the PHPList install that I’m aware of. It worked last Friday and is failing today. No new versions of PHPList were installed, no settings were changed, nothing. All of the emails are coming back as failed:
Error sending email to [emailaddress] SMTP Error: data not accepted.SMTP server error: DATA END command failed
However, the emails were successfully being sent out. It ended up requeuing the message and resending it to the first batch of emails every hour. I ended up with 10 copies by this morning. (Fortunately it was only one chunk of the list that appeared to be resending, and not the entire list.)
I tried a simple ‘send test’ to one email and it also failed with the same error.
IIRC it ended up being an SMTP timeout setting. PHPList was not receiving the reply in time and thought the message was not delivered. I tweaked this setting:
//# Smtp Timeout
//# If you use SMTP for sending, you can set the timeout of the SMTP connection
//# defaults to 5 seconds