Mail app requests password when already saved

I have several different computers/devices set up to regularly check my work email. Of course that means that sometimes 2 different mail clients will collide when trying to check that mail box. On my Windows systems I use Firefox and it will just "overlook" the locked mailbox when it is automatically checking mail. When manually checking email, it will tell me the mailbox is locked. On my iPhone, it too will tell me the mailbox is locked. All well and good. However, on my MBP using the mail.app, it continually asks me to enter the password for the mailbox which is saved in the set up.

Not sure I'm making myself clear - basically I just wish the mail.app would give me the correct info (locked box) instead of telling me the password is wrong and to enter it again.

 

K will give it a try - thanks

But one more thing - when the mailbox is not locked by another system, mail.app proceeds without any issue and receives any new emails.