Can I monitor an external mailbox without effecting techmail?

Environment:

All sites, techmail, mailboxes, external mailboxes. 

Issue:

Techmail is not pulling messages, even though I can see them in an external client. 

Resolution: 

When an email arrives in your external mailbox, it is set to new & unread. If you then use an external client -such as Outlook- to examine what messages there are in the mailbox, it is going to use POP to pull the messages in the mailbox and then mark them as pulled. If techmail comes along after that and attempts to pull messages from the mailbox, it will see only those messages which have not been previously pulled --it will not re-pull them. Each time you examine the mailbox in Outlook or other external client, you are preventing new messages from being pulled by techmail.

If you want to look at the current state of the mailbox you should only use a web portal, as that will generally not mark messages as having been pulled by POP. Further, if you open any particular messages, those will be marked as read. Messages in this state are also not pulled by techmail, so you should also not open any individual messages, even in a web portal.