if (option (OPTUSEDOMAIN))
if (From) adr = rfc822_cpy_adr_real (From); else if (option (OPTUSEDOMAIN))
static ADDRESS *mutt_default_from (void){  ADDRESS *adr = rfc822_new_address ();  const char *fqdn = mutt_fqdn(1);    /* don't set realname here, it will be set later */  if (option (OPTUSEDOMAIN))  {    adr->mailbox = safe_malloc (mutt_strlen (Username) + mutt_strlen (fqdn) + 2);    sprintf (adr->mailbox, "%s@%s", NONULL(Username), NONULL(fqdn));  }  else    adr->mailbox = safe_strdup (NONULL(Username));  return (adr);}