My Mail.app is configured with three IMAP accounts and four SMTP servers. (Each SMTP server is for a particular network connection.) Every 10 minutes, Mail.app polls the SMTP servers to test connectivity:
That by itself isn't a problem. The issue is that these two SMTP servers require usernames and passwords. Those credentials are stored in the account keychain, so every 10 minutes I'm prompted to unlock my account keychain. That is six interruptions an hour, and is quite annoying. Is there any way around this problem?