Is not an imap4 mail server

IMAP4 (Internet Message Access Protocol version 4) is a protocol used for accessing and managing email messages on a mail server. It allows clients to connect to a mail server and retrieve, send, and manage email messages.

If you're saying that "is not an IMAP4 mail server", I'm assuming you're referring to a specific mail server that does not support IMAP4 protocol.

Here are a few possibilities:

1. POP3: The mail server might only support POP3 (Post Office Protocol version 3), which is another protocol for retrieving email messages. POP3 is less common than IMAP4, but still widely used.
2. SMTP: The mail server might only support SMTP (Simple Mail Transfer Protocol), which is used for sending and receiving email messages. SMTP is a protocol for transferring email messages between mail servers, but it's not designed for accessing and managing email messages on a mail server.
3. Other protocols: There are other email protocols, such as Exchange Web Services (EWS), Microsoft Graph, or proprietary protocols used by specific email services. If the mail server doesn't support IMAP4, it might use one of these alternative protocols.
4. Custom or proprietary solution: In some cases, a mail server might use a custom or proprietary solution for managing email messages, which doesn't support standard email protocols like IMAP4.

If you're trying to access a mail server that doesn't support IMAP4, you might need to use a different protocol or client software that supports the mail server's protocol.