Can I extend my Thai visa by post at MTT instead of in person?

A user shared their experience of successfully obtaining a 30-day extension for their travel visa (TV) at the MTT without being asked for their TM30 form, which they had previously sent by post. They mentioned that this could be a convenient option for those wanting to avoid an 800THB fine or those who may not have the time to attend in person, especially since the online system for processing is currently down.