I have Mac/Sierra and suddenly have problems receiving mail. My accounts are with PlusNet, one [email protected] with password and an alias second account [email protected] with another password. Now Mail will not recognize the second account and I cannot receive mail from it. PlusNet have been working on this for over a week but no success. I have carried out their settings to the letter, being User P... and then P....+s.... but nothing works. Any help appreciated as this is causing major problems for me.