The invitations I really want are long and narrow (envelope is 3 1/4 inches wide by 8 1/4). The reply card envelopes are 3 1/4 by 5 1/4. Post office requires at least 3 1/2, so that leaves me a half inch shy for both. But.. they sell these invitations and said they aren't aware of any problems.
Have any of you successfully mailed something technically slightly too small for mailing?
I would like to just substitute some larger envelopes, but I can't find any long enough for the invitations that aren't excessively wide. Any suggestions?