If you’re seeing errors in Apple Mail after the upgrade check the following;
- Your computer might be looking at the old server. To fix this, clear your DNS cache. If this does not fix your problems, your ISP is caching an old record. Large ISP’s can take up to 72+ hours to refresh their DNS servers. To fix this, change to a free DNS service like [[OpenDNS and Google Public DNS]].
- Check your mail settings are correct in Apple Mail [[How-to check your incoming and outgoing settings]].
- If you are using IMAP then you will need to set your folder prefix. See [[How to set IMAP Prefix in Apple Mail]]
- Check email authentication is enabled. [[How-to enable SMTP Authentication]]
- Try changing your sending port: [[How to change SMTP port number]]
- If you receive ‘The POP server doesn’t support X-APOP authentication’ see [[How-to fix X-APOP authentication in Apple Mail]].
If you continue to have problems please open a new support ticket detailing the problem.