your account name is the name of your mailbox, if it was an m######, then that goes in there, or the other name that was provided, since you don’t have a m######, also, don’t put the @mycomain.com in as your account/user name, just where it asks for your email address.
your incoming mail server is mail.yourdomain.com
your outgoing mail server is USUALLY mail.yourdomain.com, sometimes you need to change the outgoing port to 587, also make sure that in the advanced option of the smtp server you select smtp requires authentication, and have the bullet selected as use the same settings as incoming mail server. (only do this when doing pop, you don’t need it for imap.
outgoing mail servers are not always the same as incoming, it really depends on your ISP internet service provider. you may want to try to set up your outgoing smtp to their addy, ie smtp.cox.net, smtp.comcast.net or smtp.bellsouth.net, etc. and make sure not to check the requires authentication. and keep your port at 25.