Today’s nugget of MDaemon wisdom comes from conversations I’ve had with a small number of customers reporting they’re unable to send outbound email to specific recipients.
Upon closer inspection of the error in the SMTP (OUT) log, there’s a message reading “SSL negotiation failed“.
It’s a bit of a niche technical one this but as I’ve had several reports of it recently I wanted to share this one with you in case it helps.
If you’re an MDaemon customer you may have started to see the following errors in the SMTP (Out) logs when trying to send email to some specific external hosts…
“SSL negotiation failed*,*error code 0x80090326”
What this boils down to is an issue where MDaemon and the remote SMTP server cannot find a common set of SSL ciphers that they both have available to use.