It looks like srs would need to use the 'URL and Filename safe' alphabet from rfc 4648, with minus and underline for the 62nd and 63rd, to provide an encoded string which all MTAs and MUAs ought to accept.
-JimC -- James Cloos <cl...@jhcloos.com> OpenPGP: 0x997A9F17ED7DAEA6 _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop