mangos-one/server — comment on commit ba00c2b54ae35ca6f81ff3a465c29cd4dae7adbb
File:  line 0
By stfx:

You are right, there is no SMSG_SHOW_MAILBOX in 2.4.3. According to Schmoozerd this is only used for argentum tournament pets. Reverted in 65bf90a