as long as you dont mind a delay on your emails an iphone will be fine
What delay ? Never had a delay with mine that I have noticed & quite often forward stuff from work or my phone & it is virtually instant
with a proper email server, IE Exchange, there will no noticeable delay unless you're timing it against Outlook, then it may be a few seconds... With a POP3 server there will be a delay, depending on the settings used to collect email, usually a 5, 10 or 15 minute wait is acceptable for most people when comparing the costs for an exchange server for a small business if they don't need it - ofc there is Office365 which is more affordable and can be competitive against POP3/IMAP services... but that's getting far to into my normal work duties for this site!
To the OP, depends if you want a phone that will last a few days while making lots of calls (old skool BB, not a touch screen BB) or if don't mind charging it up during the day and run the risk of it running out at an inopportune moment if you aren't able to charge it, it also depends on what technology powers your email at work... most modern smart phones can connect to pop3/imap/Exchange in some way and depends on what other features you want.
and getting an iphone because "ever other bugger seems to have one" isn't a good enough reason to get one

OFC you can still use your BB for work email & calls etc if it's battery lasts days and have an iphone/android/windows phone for non-work sh!t.