Our mail sending service (mailchannels.com) has advised me:
I noticed that the email where the "From" header lacks a display name (DN). The "From" header typically contains the sender's email address and optionally their display name. Kindly add proper display name with "From" header while sending emails. Please try to resolve the aforementioned issue from your end in order to avoid similar false positives in the future.
The correct From header with the proper Display Name will be like (for example) Admin admin@domain.org
I have a From Name and From Email address set in both the Configuration: Mail Configuration and in the Sender Information for every newsletter. I would have thought acymailing would take the Display Name from there. However, I tried changing the From Address to Adminadmin@domain.org as suggested but acymailing won't allow this.
I don't think this has caused any issues in the past but would like to resolve this to avoid any future issues with MailChannels.
I appreciate this is an old version of AcyMailing (Enterprise 5.13.0, joomla) but is this an issue or is there a way to ensure a Display Name is added?