My T has said that to me before but I always wait until the next appointment, but that's my own preference and nothing to do with my T. I'm more likely to share with family or a friend so I haven't felt a need to tell her before the next session. If you feel a need to contact your T, however, I think it's totally fine. I'm with Stopdog in that it bothers me when Ts tell clients they aren't "allowed" to email or call. When any professional gives contact info to a client, I think it's expected that the client will use it. A t can specify that they don't do therapy over the phone or email and that they might not answer after hours or on weekends. Anyway, I think so long as you're ok with the possibility that he may not respond until your next session, I wouldn't over think it and just email, call or text him.