Spark Mac email client
 

Hi
I use fastmail for my email and on my Mac would like to use Spark as a desktop client (I currently use the macOS Mail client), but so far have been unsuccessful with setting up Spark. I keep getting errors "A stable connection to the server could not be established" even though Mail itself has no problem. If it's not that error I get "Unable to authenticate with the current session's credentials". Anyone successfully set up Spark on a Mac?

I assume:

• You are trying to establish an IMAP connection to imap.fastmail.com;
• you specify your entire user name and an app-specific password, not your main account password;
• you have ensured that the port number is 992 or 993; and
• you are trying to use SSL or TLS.

Double check the above, and fiddle with the SSL/TLS settings. Some clients allow multiple flavors, and I think FastMail wants SSL (initiation of a secure connection immediately) rather than TLS (switching to a secure session after the initial connection is made using STARTTLS).
Also, be aware that the error may be with the SMTP connection, not the IMAP connection. For SMTP, you need authentication and SSL with smtp.fastmail.com on port 465.

Hi, thanks for the reply. Those are the settings I'm using, according to the fastmail documentation they seem to allow STARTTLS for smtp but you need to specify port 587. But I've tried both SSL and STARTTLS (the only 2 options available) and still get the same error "Unable to authenticate with the current session's credentials".

Be sure you pay attention to the application password:
https://www.fastmail.com/help/clients/apppassword.html

You should create a new application password for your Spark email client. Use your full Fastmail login email address and the application password you set up for Spark. The error message you are seeing "Unable to authenticate with the current session's credentials" sounds to me like an authentication problem which may be due to using the wrong password.

Bill

Got it now, I had a fixation on app-specific password in iCloud even though I couldn't so how at this stage Spark would need that, anyway I've found the 'generate app password' within FasatMail settings page so all is hunky-dory! Thanks.