I send email from a me.com email address through Gmail. Recently a large number of my emails are not arriving at the recipient and when I contact them by phone to check, the email is in their spam folder. In some cases it has not arrived at all. These are people who are in my contacts list (and I'm in theirs) in some cases, and in others they are new recipients that are not expecting emails from me (and therefore cannot add me in advance to their contacts). I only ever send to one, or two, recipients at a time so not bulk emails. It is happening when I send from Iphone gmail, Windows Easymail for Gmail, and Mac OS Gmail platforms. It even happens sometimes when I reply to an email I have in my Inbox. I have no way of knowing if my emails are being received which is obviously an untenable situation for work, and for home, email.
Can anyone explain what is happening, and what I can do to stop it?