I have two computers on the same netwrok, both with licensed emClient Pro installed. After several years of working fine, one system will almost alway fail at sending an email if it has anything other than simple text content. The error is:
[SMTP] An attempt to connect to [[email protected]](mailto: [email addresss]) fialed. This could be caused by temporary server unavailability or incorrect settings. Do you want to check the settings?
If the settings are checked, it reports Port: 587, Security Force usage of SSL/TLS.
I have done the diagnostic test of SMTP and it always reports success.
In looking at the SMTP log, at the failure it reports an exception such as decryption operation failed or unable to write to remote host. Connection was closed by remote host.
Sometimes a message will sit in the outbox for several hours and then finally go out. In the meantime that computer is able to use the internet etc. Once an outgoing message fails with this error no other messages can go out.
The other computer with same setup, on the same router (both hard-wired) never has this problem.
This creates a termendous problem because we cannot send useful information beyond a little bit of text.