I am also getting a lot of these warnings. Setting the log level to Error means then it won't log the other warnings, like Failed login attempt or Agent Password Reset., Is there a way to track down the cause, is it due to same image used, like an image in an email signature? Or is there a way to disable this specific warning if it's no big deal? My log is also filling up.
(Otherwise we're very happy with osTicket, having moved from Spiceworks due to the Office365 MFA changes imposed at end of 2022)
EDIT: p.s. I see that domingolima has also asked this but same reply https://forum.osticket.com/d/102163-unable-to-retrieve-email-inline-image
so ideally it'd be good to have an alternative solution than set logging level to error if possible.