quote_local_part: ${quote_local_part:ab\cd"ef}
quote_local_part: ${quote_local_part:}
rxquote:${rxquote:aZ09_,-Q} ${rxquote:ab*cd} ${rxquote:ab\cd"ef}
+hexquote: ${hexquote:\
+ \001\002\003\004\005\006\007 \010\011\012\013\014\015\016\017 \
+\020\021\022\023\024\025\026\027 \030\031\032\033\034\035\036\037 \
+\040\041\042\043\044\045\046\047 \050\051\052\053\054\055\056\057 \
+\060\061\062\063\064\065\066\067 \070\071\072\073\074\075\076\077 \
+\100\101\102\103\104\105\106\107 \110\111\112\113\114\115\116\117 \
+\120\121\122\123\124\125\126\127 \130\131\132\133\134\135\136\137 \
+\140\141\142\143\144\145\146\147 \150\151\152\153\154\155\156\157 \
+\160\161\162\163\164\165\166\167 \170\171\172\173\174\175\176\177}
substr: ${substr_3_2:rhubarb} ${s_-5_2:1234567} ${s_-5_2:12} ${s_-3_2:12}
substr: ${s_3:rhubarb} ${s_-2:rhubarb}
substr: ${s_1:}
> quote_local_part: "abcd\"ef"
> quote_local_part: ""
> rxquote:aZ09\_\,\-Q ab\*cd abcd\"ef
+> hexquote: \x01\x02\x03\x04\x05\x06\x07\x20\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x20\x10\x11\x12\x13\x14\x15\x16\x17\x20\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x20!"#$%&'\x20()*+,-./\x2001234567\x2089:;<=>?\x20@ABCDEFG\x20HIJKLMNO\x20PQRSTUVW\x20XYZ[\]^_\x20`abcdefg\x20hijklmno\x20pqrstuvw\x20xyz{|}~\x7f
> substr: ba 34 1
> substr: barb rhuba
> substr: