For the past 3 months, messages sent to firstname.lastname@example.org are being rejected and returned with a message like this:
550 permanent failure for one or more recipients (email@example.com:blocked)
I work for a hospital and we used Google as our e-mail service to send out alerts and notifications to staff. Messages sent to tmomail are being blocked.
I have contacted t-mobile support by phone multiple times but the staff answering the phone are not able to address the problem, and only focus on a single phone number. Reading other similar posts here, I see that somehow you have to call in and get added to a 'approved sender' list. Can somebody tell me what number to call for support that would understand this issue?