Please help us help you and fill where relevant:
LimeSurvey version:

• LimeSurvey version6.13.0
• LimeSurvey build250415
• PHP version8.2.28

Own server or LimeSurvey Cloud: Own
Survey theme/template:
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WAS THIS: forums.limesurvey.org/forum/installation...-survey-admin-emails


Hi there - I have production and development LS instances and with one instance only I'm having an issue with email settings where the global email setting is not accepting an SMTP username unless it is in the form of an email address. However the other server accepts a non email address format user name just fine.

LS instance 1:
Smtp host: mail.somehost.com:465
SMTP username: example

===>Test email and survey emails work just fine

LS instance 2:
Smtp host: mail.somehost.com:465
SMTP username: example

===> Invalid address: (From): example

If I change the username to example@example.com, LimeSurvey attempts the send (and then fails to authenticate because the username is now incorrect as it contains the domain name.

As far as I can tell all the other relevant settings are the same, tried turning off ModSec as well.

I saw one old forum post here that potentially details the same problem.
forums.limesurvey.org/forum/installation...up-sending-of-emails

Be very grateful for any ideas especially given the error is thrown on one instance of LS and not the other!