eM Client rejecting sent emails as spam

eM Client is rejecting all my optonline emails as spam but allowing same content to send on Gmail.

eM Client can’t do that, rather you mean your email provider is rejecting messages you send as spam.

They will give a reason why. Can you provide that information?

5.7.1 Spam detected by content scanner. Message rejected (long number)

These same messages go thru when sent from my iphone or directly from my computer optonline, but get rejected when sent by emClient.

Sometimes there is a link in the error to a web page that describes what the objectionable content is, or a description. If not, that is something you will need to ask your email provider about. Your IP address could even be on a blacklist, but they will be able to tell you more.

Hi everyone,
The same for me, my email is bounced back (only for 1 recipient, and I used to send him email with EM Client before…) but it works when I send it via Outlook (MAC) ! How bizarre (and anoying…). Can you help ?
Thierry