Syntax error from CiviMail

Question

I have set up outbound mail and individual mails go fine. But I can't get the CiviMail working to a group. All the members bounce with a Syntax error. I am running CiviCRM 4.7.22 on WordPress 4.8.2. I've included addresses to recipients on different servers so don't think its a remote problem. The Syntax bounce is supposed to indicate an SMTP transaction error, but things work fine when its just a single email to one of the same contacts.

I have seen other SE posts that might relate, but they are with different configurations CiviMail not sending mails in 4.7.6 / Drupal 7 "DB Error: syntax error" and help on wordpress for send mailling

Answer 1

This is exactly like the problem I am having. I worked with Siteground support and they couldn't figure it out. They suggested to throttle the outbound to a very small number, which would work for small batches, but ultimately would fail. At the suggested throttle it would take 8 hours to send out an email to my 500 members.

Answer 2

civimail (for some reason) would not accept the syntax on newsletter bulk mail so I reset my outgoing email methods. I am using drupal 7.64 and civicrm 7.x-5.10.4 on siteground. I was sending LESS THAN 500 emails.

I switched my civicrm outbound email send option from -mail- to -smtp- with settings as follows (1) smtp server: ssl://smtp.gmail.com (2) port: 465 (3) authentication: yes (4) email: my gmail email address (5) password: my gmail password.

Then I had to go to gmail settings and add my siteground account as an alternate sender. In gmail account : (1) click on -settings- "cog"; (2) select -accounts and settings- tab; (3) select -check mail from other accounts- then (4) add your siteground email details: (a) email address; (b) password; (c) pop server (mail.your_site.com); (d) port 110

worked for me to send unblocked bulk mails with free gmail service:-)

Answer 3

I have worked round this by installing an external mail provider SparkPost as suggested by a similar post Can't send or test bulk mail, but test mail succeeds in System Settings / Outbound email / SMTP . I don't see this as a full solution as it adds a lot of complexity. I don't think that my hosting provided (SiteGround) is particularly blocking it so still think that it must be some configuration error. Will come back to this when I have more time.

Answer 4

VERP is only applied to CiviMail emails and might lead to such behaviour.

Try disabling VERP if you are experiencing delivery issues with CiviMail but "regular" / transactional CiviCRM mails work OK.

Administer > CiviMail > CiviMail Component Settings > Track replies using VERP in Reply-To

Answer 5

As noted above the problem went away when I tried again some months later so its resolved but no idea why.

Answer 6

I experienced this problem too, and it was a mismatch of PHP versions on command-line vs. web server: Mailing Bounces 100% with "authentication failure" or "failed to set sender"