I just installed Fedora 28 KDE, and am having an impossible time sending any emails at all. At first, I set up 2 email clients (1 gmail, 1 icloud) and the gmail account would send fine, but whenever I would try to send an email from my icloud mail, it would always try to use my gmail's smtp server because KMail sets a "default" smtp server (whyyyyyyy). So I nuked all my accounts and reset up from ground 1, so I could at least get gmail sending, but now I am endlessly faced with a "Failed to transport message. Server error" message. So my problem here is turning out to be 2 issues right now. 1: how do I get the "Failed to transport message. Server error" error to stop (gmail via oauth2 authentication) and 2: once I get problem 1 solved, how do I set up more than 1 email client? I don't want a default smtp server, I want each account to use its own smtp configurations

Hi,

you can configure which "transport" (or outgoing account) you want to use with each Identity. So if you have "Personal" and "Work" identity and "Gmail" and "iCloud" SMTP transports, you can configure the transport to use by default for each identity in the identity settings.

Regarding Gmail not working, sending emails via Gmail does not support OAuth yet, you will need to either type in your password, or if you use two-factor authentication, you will need to generate an app-specific password for your Gmail SMTP. OAuth for SMTP will be introduced in the next feature release in August.

Awesome thank you. Is there any reason why I have to go to each account and tell it to use a different default account? And will the OAuth feature be backported to 5.12.x?

Currently the account management in KMail is a bit clumsy and the three things (identities, incoming accounts and outgoing accounts) are very detached so setting it up requires a lot of going back and forth. We are planning to streamline it a bit more in the future, but we don't have a clear vision yet.

Regarding the backport, 5.12 is the version of Plasma. KDE PIM follows KDE Applications releases (currently 18.04). And we will not backport the feature to a current release, the change is too big for that.

Sorry to interfere and I am not sure I have the same issue, but...
My kmail can't send mails from outside my server's network, only from inside, and returns messages with "Server error".
But Thunderbird and Evolution with exactly the same parameters sends perfectly.
Can you recommend me something to solve this?

It is september already and after a clean install on Neon kde user edition the smtp part of kmail doesn't work with OAuth...
When can we expect this to happen? It is not clear to me...
Thanks