This is long winded sorry.Last night I opened an

this is long winded sorry.Last night I opened an email thought it was a name I knew.But then I got whole page in my in box from the postmaster saying I had messages that weren't delivered,but I hadn't sent any messages,next thing I looked and all the messages I GOT from the postmaster were gone I didn't delete them.Also I had sent 2 messages this week,but when I looked in my sent mesages they were gone,again I didn't delete them.So I thought I would send an email to see if it would be in my sent messages,but when I did it said I couldn't send anymore emails as I had reached my limit for 24hours,but I hadn't sent any emails at all yesterday? I changed my password hoped that would put an end to it,but again today I have had 3 messages in my in box from postmaster saying again I have emails that weren't delivered yet again I haven't sent any.I have had this email address for 5 years now andnever had a problem before.Please can you help and advise me.Thankyou