In San Carlos, there is a Post Office in the small strip mall beside Hambone’s insurance. It is open Monday to Friday from 9:00 am – 2:00 pm. It is closed on national holidays and on Postman’s Day, November 12. It does not sell US or Canadian stamps. You must use Mexican stamps to mail a letter from Mexico. It may take up to 4 weeks to get a mailed letter to the US from San Carlos.
Rosa’s Cantina has a mail drop box
People heading north often will take your letters (with USA stamps) and mail them when they get to the States. Rosa’s Cantina has a mail drop box, and travelers headed north will obligingly take the mail deposited there to the States and mail it for you (although once in a while they are too relaxed from their vacation to do it right away!).
If you want to receive mail in Mexico, you can rent a mailbox at the Post Office. You must pay the annual rent amount, regardless of when you begin to rent it (they do not pro-rate months). They will tell you your mailing address (it will be a PO Box #), and mail delivered here from Canada or the US will take approx. 3 weeks. We do not recommend that you have anything of value sent to you, however books and small packages will likely be shipped with no problems – just remember that there is no guarantee.
The most reliable and fastest way to send or receive packages is by DHL, a worldwide delivery service. The DHL office is in Guaymas. If you are sending a package or envelope, do not seal it until the DHL representative has checked its contents.