Every day a few incoming mails are missing on my Macbook Air (10.13.3) when I compare to my Iphone 6! It is random senders and random times and it occurs in 3 out of 4 mail accounts. Today I counted to 4 missing mails spread out over the day. Yesterday it was all the mails for a 10 minute period. It has been gping on for a few weeks. I use Mail and my email provider is .one. Does anyone know what is happening? What can I do?