Access to mailbox via POP3 / IMAP and SMTP servers can automatically switch off in these cases:
1. If your password was hacked and your account is being used to distribute spam. In this case, on your e-mail can come letters from "Mail Delivery System". Before you set on the settings (open the mailbox of e-mail protocols) you necessarily have to change the password secret question and answer to it.
2. If you exceed the limit of sent messages per day (on Inbox service)
3. Perhaps your mailbox became inactive
4. If the user within two months didn’t use POP3 / IMAP protocols
In case you did not find your answer contact us