Problem getting automatic emails from WordPress

I have several WordPress driven sites; have used WordPress since 2006. Recently – over the past year or so, I've had a LOT of trouble receiving emails from WordPress for password resets (the main reason I get emails from WordPress). It's incredibly frustrating. It's not limited to a particular email address or a particular website, and I do not have this issue with other automatic emails so it's not a client-side issue. My sites are hosted on Dreamhost. Dreamhost support has not been helpful. Has anyone else had this problem?