My corporate email is hosted by Office365. I think KMail is far more productive an email client than the Outlook Web Application (OWA), so I use IMAP to receive email and SMTP to send email.
I can receive email fine, but on certain networks I cannot send mail. For example, GoGo Inflight Internet (gogoair) or some of the corporate networks of my clients. On these networks, I get the following error from KMail:
Failed to transport message. smtp.office365.com: Socket operation timed out
Sending email to Gmail via SMTP through the same port (587) works fine.
I have configured KMail to send email as follows: Outgoing mail server: smtp.office365.com Port: 587 Encryption: TLS
I have tried:
- Lengthening the socket timeout
- Disabling IPV6
- Disabling TCP Timestamps
but I see no change in behavior.
I don't see anything relevant in the journal, akonadi logs, or .xsession-errors
Anyone have a suggestion on what else I can try?
openssl s_client -starttls smtp -connect smtp.office365.com:587