Forums › Other › Housekeeping › Email address › Reply To: Email address
Email addresses aren’t case sensitive (neither are URLs for that matter).
This is factually incorrect.
URLs can be case sensitive depending on the webserver software. All levels of the domain (from TLD onwards) are case-insensitive but plenty of URLs are case sensitive.
Because of this the domain part of an email address is always case-insensitive but, as per RFC 5321 2.4, the local part of an email address can be case sensitive.
If someone has advised you otherwise I would worry about their technical competence. And given that knowledge of RFC 1035 section 3.1 and RFC 5321 section 2.4 is very well-known, any developer that thinks email addresses are not case sensitive is unlikely to be technically competent enough to write secure public-facing software.
- This reply was modified 55 years, 7 months ago by .
New to Head for Points?
Welcome! We’re the UK’s most-read source of business travel, Avios, frequent flyer and hotel loyalty news. Let us improve how you travel. Got any questions? Ask them in our forums.
Latest Forum Posts
-
Matlo on I made a site to help find good value Virgin Atlantic redemptions – vseats.io
-
Richie on Chat thread – Saturday 2nd August
-
JakeWS on Chat thread – Saturday 2nd August
-
NorthernLass on Chat thread – Saturday 2nd August
-
NorthernLass on Routes with decent J availability for summer 2026
-
NorthernLass on Changes to Iberia redemptions
-
Blair Waldorf Salad on Routes with decent J availability for summer 2026
-
jf256 on Corporate Amex Card – 2 year reset on Amex MR
-
JakeWS on Chat thread – Saturday 2nd August
-
AndyGWP on Paying off Skoda car finance
Check reward flight availability instantly for free!
Booking a luxury hotel?
Our luxury hotel booking service offers you GUARANTEED extra benefits over booking direct. Works with Four Seasons, Mandarin Oriental, The Ritz Carlton, St Regis and more. We've booked £1.7 million of rooms to date. Click for details.