My sister works for a company who allow them to use their work email account for personal use too - It is actually stated in the company handbook that this is accepted.
She has just found out (as she received a return read receipt on a mail she sent to someone), that the IT dept in fact read some of these personal mails. Is this allowed ?
It's a bit of a grey area. I work in IT and we monitor all emails coming in and out of the building. As part of this, we can see the subject heading of each mail to see if it's spam or rubbish.
Occasionally we look at people's emails if we suspect they are spam or abuse but if we supect someone of regularly abusing the email system, we would ask them to open their emails with oine of us stood by. If they refuse, then we would go in and look anyway.
It's very subjective but if I saw someone emailing a non-work address more than say 10 times an hour or sending chain mails on, I would probably have a look in and see what was happening.
It all depends though and I have to use my judgement. As it's Christmas, I'm a little more lenient and expect that people are emailing each other best wishes but during a normal week, I would be more vigilant.
I think we're in the same position, staff can use their work computer, email addresses etc for personal use if they want, but they have to realise that they may be monitored. It is, after all, company property and company email addresses.
Abuse of the email system would, in our case, be too many personal emails, inappropriate emails (could be abusive or pornographic content etc), or anything offensive. Usually, its just too much time spent on personal emails during work time.