I got a text from someone named "Jo".  It said "I met you last week.  Give me your email address so I can send you a picture"

There was no such meeting, no idea who this person is.

Txting scam, very popular nowdays. Ignore and block.

B is right.. most likely trying to slip you a porn spam and/or link! If you don't have a app on your phone, there are a lot of free apps out there - even for straight talk and Tracfones.

For text messages: forwarding any text message spam you get to the short code  “7726,” which spells “spam” on most phones, to alert your network operator to the abuse. ATT won't accept 7726 But they will accept BLOCK and return a message that the web site is blocked. forward the texts to 7726 or BLOCK, depending on your phone carrier.