Whenever possible, use the TLS-secured version of the IMAP protocol (IMAPS). IMAP is generally more modern and more reliable to access your emails on the remote mail servers. TLS encryption (used in IMAPS and POP3S) prevent that the user password and the message content is sent in clear text.
The POP3 protocol does not include a specification for message read or unread indicators. To overcome this limitation, any POP3 client must access all messages at every interval and select the messages to be processed based on a 'last message processed' indicator. This is done in Squirrel with a hidden time stamp field added to the mail account subscription document.
To support customers migrating entire POP3 or IMAP mailboxes to Domino, the option 'Mail Migration' may be used to read all messages once during the next interval. This option is then reset at the next message fetch interval.
If Squirrel encounters any error while processing a mail account subscription, it will disable this document to prevent future error messages. The last error message is saved in the mail account subscription document and an HCL Notes email message is sent to the user to inform of the error. After the error has been corrected (e.g. wrong password), the mail account subscription document must be manually enabled again to resume the processing for this subscription. Other errors (e.g. connection timeouts) are reported on the console and the operation is retried at the next interval.