How to configure a mail client for a mailbox created in Plesk?

Navigate to Domains > example.com > Mail > Mail Accounts

Press on the Mail Client Setup button on the right of the desired mailbox:

Press on the the type of platform you wish to connect this mailbox with for detailed instructions or press on the Manual setup tab if you want to set up the mailbox manually:

Use the displayed information to set-up your mail client:

Note: Apart from the options below, if you have enabled mail submission via port 587 for Plesk on Linux or Plesk on Windows, you could also configure port 587 with STARTTLS for secure SMTP transactions via external mail clients.