Anyone know a location of a Post office near nimmanhaemin or old city? I read somewhere some of the post offices are fake so wanna make sure to get a real one. I also need envolopes and packing tape.

real post office (as opposed to contract sub-station) "franchise" in that area would be downstairs at KSK right next door to the police box and night club. no packing tape there but you can go up to the paper shop on the 4th Floor attached to Central and get supplies there.

don't forget your passport when you go to that branch as they will demand your original passport to even send a letter.

Or you could go to the post office inside the grounds of Chiang Mai university. Envelopes are available there.

http://www.embracechiangmai.com/index.php?page=postalservices

There is a post office, official and complete with inconvenient post office hours, on Thanon Samlarn, the north-south road that runs outside the entrance to Wat Phra Singh, the Wat at the end of Rachadamnoen/Walking Street. It is about 200 meters south of the Wat on the east side of the street. I live on Nimmanhamin, that is the one I use if the mail is important.

Edit: I think this is the Prasing post office at the bottom of the list at the link provide above. It says the street is T. Phra Singh. It may be, I just find the entrance to Phra Singh and head south a short distance, I don't pay attention to street names.

Yes, that's the Phra Singh Post office, the main post office in Chiang Mai I believe. At least that's where my registered post always ends up if I'm not at home to sign for it, and where it comes from originally (according to tracking info).

http://www.embracechiangmai.com/index.php?page=postalservices

that list represents a fraction of the post offices in Chiang Mai. the main P.O. is on Charoen Muang. the main P.O. for Logispost is Kamthieng branch.