added --version flag

mailfmt.py

@@ -15,6 +15,7 @@ import argparse
 import re
 import sys
 import textwrap
+from importlib.metadata import version
 
 
 def main() -> None:
@@ -93,6 +94,13 @@ Contact   : daniel@ficd.sh
         """,
         formatter_class=argparse.RawDescriptionHelpFormatter,
     )
+    parser.add_argument(
+        "-v",
+        "--version",
+        required=False,
+        help="Print version info and exit.",
+        action="store_true",
+    )
     parser.add_argument(
         "-w",
         "--width",
@@ -162,6 +170,9 @@ Contact   : daniel@ficd.sh
         help="Output file. (default: %(default)s)",
     )
     args = parser.parse_args()
+    if args.version:
+        print(version("mailfmt"))
+        exit(0)
     width = args.width
     should_check_signoff = args.no_signoff
     should_check_signature = args.no_signature