Hi baronne,
The Safe way would be creating profiles on your mail clients for your laptops.
1 - Road Profile: pop.yourdomain.zzz & smtp.yourISP.com
2 - Office profile: pop.yourdomain.zzz & smtp.yourdomain.zzz.
If your laptop are running windoz mail client like outlook you can use the two profiles with the on the same "pst" file.
It a safe way that we use in our company with laptops on the road.
ciao.

maaz