Subaddress char MTA option

Alias and address MTA options:  (list of integers)
The  MTA option specifies the ASCII  representation of the character to use as the subaddress indicator in the mailbox portion of an address. The default is to use the plus character, +, which has ASCII representation 43.

Note that internally the   channel  always expects to see a plus character, +, and is normally always passed the plus character due to the    MTA option, regardless of what character is used "externally" as the subaddress separator character.

See also:
 * subaddressexact Option
 * ims-ms channels
 * delivery_options MTA Option
 * Sieve subaddress extension
 * Alias and address MTA options