"A POP3, SMTP and IMAP email server"
To have an email server is highly recommended to use a program such as MDaemon to manage them correctly, thus offering a practical operation and considerable time savings.
Its main advantage is to combine all the functions in a single interface and window, so the convenience is maximum at all times when managing all your email accounts, whether reading emails, answering them, downloading their attachments, and so on. Every event is recorded in a kind of log. On the other hand, MDaemon takes care of avoiding both SPAM and viruses, which is greatly appreciated.
The manager can be configured to adapt one hundred percent to your needs, the filters being very relevant in this task of customization.