My web mail not receiving/Sending some e-mails.

[rashidkeezhal]

Today morning my clients office some staff cannot find any emails their inbox. and some recipients not received any mails from these email accounts. also i checked in junk folder and web access. but afternoon i sent some emails to some email accounts it delivers successfully (but after 10-15 minutes) what could be the problem?

 

[A Guy]

Hello rashidkeezhal, I'm not a mail expert but we will need more info to try and help you. What email client are they using? How are they accessing these emails? this is not happening to everyone, only a few have problems? is there anything unique about the users with problems you can identify?

A Guy

 

[rashidkeezhal]

Thanks A guy.
They are using outlook 2010, it's a webmail named fastweb.it, only few have problems. and there is no unique problems. which means user did not receive some emails(even from same sender). Sending message delay to deliver or not delivered some e-mails.