Lines of smtp2tg.toml.example from check-in 14ef340959 that are changed by the sequence of edits moving toward check-in 0acb6536ae:

                         1: # vi:ft=toml:
                         2: # Telegram API key
                         3: api_key = "YOU_KNOW_WHERE_TO_GET_THIS"
                         4: 
                         5: # Telegram API gateway (when you are running your own)
                         6: api_gateway = "https://api.telegram.org" # <- note no trailing slash
                         7: 
                         8: # where to listen on (sockets are not supported since 0.3.0)
                         9: listen_on = "0.0.0.0:25"
                        10: 
14ef340959 2026-01-01   11: # whether we need to handle unknown adresses
14ef340959 2026-01-01   12: # - relay: send them to default one
14ef340959 2026-01-01   13: # - deny: drop them
14ef340959 2026-01-01   14: unknown = "relay"
14ef340959 2026-01-01   15: 
14ef340959 2026-01-01   16: # default fields to show in message header
14ef340959 2026-01-01   17: fields = [ "date", "from", "subject" ]
                        18: 
                        19: # which domains are allowed in addresses
                        20: # this means that any unqualified recipient "somebody" will also match
                        21: # to "somebody@each_domain"
                        22: domains = [ "localhost", "current.hostname" ]
                        23: 
                        24: # default recipient, should be specified
14ef340959 2026-01-01   25: # still can be a user, channel or group
                        26: default = 0
                        27: 
                        28: [recipients]
                        29: # make sure you quote emails, as "@" can't go there unquoted. And by default
14ef340959 2026-01-01   30: # we need FQDNs
                        31: "somebody@example.com" = 1 # user id's are positive
                        32: "root" = -1 # group id's are negative
                        33: 
                        34: # to look up chat/group id you can use debug settings in Telegram clients,
                        35: # or some bot like @getidsbot or @RawDataBot