Just stumbled on an interesting rant by Jetse de Vries (formerly of Interzone, now the man behind Outshine twittermag and the Shine Positive SF anthology). He starts off rambling about national postal services who screw over their small private customers and focus on large commercial contracts instead.
I very much sympathize, because mailing off manuscripts to overseas publishers is something I haven't even started doing yet, because of the cost and the hassle involved. As long I have online submissions options I will pursue those first.

Of course, Jetse being Jetse, he turns the rant into a valid point on the future of SFF magazine publishing...

SF magazines are one of those 'small' customers: sending out a few thousand (let alone a few hundred) is not enough to get a bulk discount. So the postal rates for them go up, considerably, as well. Therefore, SF fiction print magazines are doomed (or more doomed than they already were): mailing costs will go up, and sending the magazines through commercial companies is even more expensive.

Read the complete article on Jetse's blog, In the Plane of the Ecliptic