This is a pretty obscure request, since there aren't many people who have this kind of problem. A lot of these email problems can be solved with more simple methods most of the time.
What is the reason that you use your carrier's SMTP server? Usually, this is the alternate server if you're using an email address from your ISP and cannot send mail through their server unless you're physically on their network.
Perhaps a simpler solution for you would be to use two separate email setups using the same address. One can be set up to use your carrier SMTP server, and the other can be set up to use your work settings. If you use the automatic BCC to yourself option, you can keep them synched with each other pretty easily. This way, you just select the account that you want to use to send mail based on where you are located.
Of course, the best solution would be to start using an email account that doesn't restrict your SMTP use based on originating network.