I’ve had a company host my website and email for the last six months or so and I’m having intermittent and silent failures where emails sent to me are not received.

• The sender never receives a “delivery notification failure” message.
• This has happened on multiple domains (@gmail.com, @microsoft.com)
• I’ve experienced it happening first hand when I sent a mail to myself from another account but I was unable to reproduce the error.
• It’s very rare (one in every 300 emails or so)
• The mails are not routed to my junk folder :)

Obviously I’m worried about the effect this has on my business – but what can I do? I don’t believe I have enough information to diagnose the problem (neither does my hosting company when I presented them with the same information) – should I switch to another host?