[OJS3.2.1.1] Rejected emails becuase of "does not meet IPv6 sending guidelines"

Hello @ctgraham @asmecher

Describe the issue or problem
Some email sent by OJS are rejected with the following return message:

Our system has detected that this message 550-5.7.1 does not meet IPv6 
sending guidelines regarding PTR records and 550-5.7.1 authentication. 
Please review 550-5.7.1 https://support.google.com/mail/?p=IPv6AuthError 
for more information 550-5.7.1 . i5-20020a5d6305000000b002358d1a27ebsi8412670wru.763 
- gsmtp (in reply to end of DATA command)

Steps I took leading up to the issue
Automated Article Review Request email from OJS itself to a reviewer’s email adress.

What application are you using?

What and how can I configure the email sending in OJS to prevent those errors in future? Will this be solved after upgrading OJS to the newest version (which we will do shortly)?


A general guide to configuring email in OJS can be found here:

In short, you must use the config.inc.php settings to specify a sender which is compatible with your (or your hosting provider’s) SFP and DMARC rules, including DKIM signatures.

What is your current email configuration in config.inc.php?

Thanks for your reply! We have this Config:

; Email Settings ;


; smtp = On

; smtp_server = mail.example.com
; smtp_port = 25

; smtp_auth = ssl
; smtp_username = username
; smtp_password = password
; smtp_authtype =

; smtp_oauth_provider = Google
; smtp_oauth_email =
; smtp_oauth_clientid =
; smtp_oauth_clientsecret =
; smtp_oauth_refreshtoken =

; smtp_suppress_cert_check = On

allow_envelope_sender = On

default_envelope_sender = our@mail-adress.ext

force_default_envelope_sender = On

force_dmarc_compliant_from = On

dmarc_compliant_from_displayname = '%n via %s'

time_between_emails = 3600

max_recipients = 10

require_validation = On

validation_timeout = 14

I’ll read your given links.