Mozilla Community

"Sorry, sir. We don't take orders from standard addresses."

Some websites inexplicably reject valid email addresses. This infuriates part of their audience, who are rejected with a message such as "Please enter a valid email". Users may try again, carefully (and correctly) entering their (valid) email address several times, before they realize that the stubborn website will never accept them, usually without even bothering explaining why or providing a means to contact the webmaster. Most users will just take their business elsewhere rather than try to complain.

There is a belief that '+' and some other characters are not allowed in the left part of an email address. This belief is unfounded, and there is absolutely no technical reason to reject those characters: the documents that specify the format of email addresses, RFC 822 and RFC 2822, treat '+' in the same way as, for instance, 'a'. Still, some websites are happy to tell their visitors that they do not trust them to write their own email address properly. When asked, incompetent or lazy webmasters often tell potential customers to... just use another address!

The meaning of the left part of an email address is up to the recipient; the sender should not care about it. '+' can be meant as a regular character, or it can be used for tagging, or whatever. In any case, it is not the sender's job to restrict the Internet standards. This behaviour is unprofessional for two reasons: you're refusing a customer, and you're showing lack of technical knowledge.

Here is the hall of shame of incompetent websites that reject '+' addresses. If a site doesn't allow you to register with a '+' in the address, please add it.

Q: So what is the right way to validate email addresses?
A: JavaScript Best Practices has a nice "isValidEmail" function that accepts all valid email addresses, even plussed addresses.

Plus Haters: Websites that cannot deal with the simplest Internet standards

Can you trust incompetent and lazy people? You decide.

  • American Express
  • Ankama
  • Argos Catalogue
  • Assedic "Caractères spéciaux interdits dans l'adresse Courriel."
  • Auto Trader
  • Bank of America
  • La Banque Postale
  • boursorama
  • Bokus
  • often handles plussed email correctly. However, the "feedback" link at the bottom of every page uses an obsolete bit of code by "S.Wijaya" [1] that fails to handle plussed email correctly.
  • Chrysler
  • CityDeal
  • CNIL ( This is the French administrative authority for data privacy; one may have thought they'd be more knowledgeable about email!
  • Cofinoga (
  • Contra Costa County Community Warning System Accepts the address but the web code converts the plus to a space, making it unusable as an address later in the signup process.
  • Cucumis
  • login/signup This is a site that actually supported plus addressing before the recent login system upgrade. So for people like me who signed up under the old system with a plus address are now locked out of their accounts. 5 emails and only reply is a generic new system has problems message. -- 11:33, 4 December 2007 (UTC)
  • ("Format de l'adresse de courriel incorrect")
  • ("Invalid email address.")
  • ( Plus, there is no way to contact them.
  • : "Le caractere [+] est interdit !" (ça a le mérite d'être clair !)
  • Facebook rejects plus addresses in an exceptionnally bad way: the sign-up form just answers that an error occurred. The helpless user is left without a hint of what or where the error might be. Actually it looks like an internal Facebook error. Thus it does not even help users who mistyped a plus, nor users who would accept to do without plus addressing if asked.
  • Folkmanis
  • France Telecom / Orange
  • They sell "e-mail marketing"... but they don't accept valid addresses. If your mailings are in their hands, you're loosing customers!
  •, a subscription handler for newspapers like the Ft. Collins Coloradoan.
  • Hertz
  • Holiday Inn hotels (+ not accepted, we're told "The Email Address you provided is in an invalid format.")
  • IceRocket
  • Worse than simply complaining that the address might be incorrect, this website's contact form says that the email field is "mandatory". Customer: "Well, it's properly filled... so what's wrong!?"
  • ( This is the official, government-run website for French tax collection. Although it is otherwise pretty well designed, this amateur-level design fault is a shame. When asked about it, they tell you to use another email address! Three years after notification, the bug, which could probably be corrected in a few minutes by someone familiar with the system, persists.
  • La Poste. The French postal service: you'd think they know something about mail. Indeed, they've conceived the worst approach I've encountered: this form does accept plus addresses, only to delete the plus and send your mails to random people! For instance, if your adress is "", the mail will be sent to "". ([2])
  • : another display of incompetence by the French government. An email address is required to get paper documentation. This address is not verified but is not allowed to simply match standards. And dont' think you can even tell them about the problem... look at the bottom: who'd expect "Informations légales et techniques" ("Legal and technical details") to be a link? Everybody? Well, it's not. No contact info.
  • Lego ( and
  • Macys ( ) Accepts +adresses on registration but can not handle them in the system so unregistering becomes impossible. Got no response on my letter to explain the problem.
  • Meetic (, "Votre adresse email est invalide. Merci de choisir une adresse email valide.")
  • Microsoft Hotmail will not allow sending mail to any e-mail address containing !#$%*/?|^{}`~. [1]
  • Microsoft Passport
  • Music Brigade recommends that the customer just use a different email address!
  • Nazareth Cross "Please fill out the entire form", it says!
  • neuf telecom (
  • The New York Times ( I emailed them about it, they said they regret the inconvenience and "We suggest that you use another e-mail address or that you contact your ISP and ask for an "alias" -- that is, another standardized e-mail address that you can use and that will forward mail to your account." -- 21:53, 5 December 2007 (UTC) [Still not fixed on 2012-04-18.]
  • And their business is... Internet access. Plus, their website doesn't give you any way to contact the webmaster.
  • Opodo. They don't accept money from people whose email address doesn't please them. Worse, their contact page does not allow inquiries about their Website: How do they get feedback? I guess they don't care. And that's not all: they don't preserve case in the address you supply (in the recap they send to you if you are motivated enough to order, your address appears all uppercased).
  • (official website of the city of Paris). says: "Le format de l'adresse mél n'est pas correct."
  • Popotamo : "L'email entré ne semble pas valide."
  • - customer service
  • Postica ( "Your email should look like,". Err... talk without knowing.
  • RealAge
  • -- the site doesn't reject the address, but it seems to crash because of it.
  • . I want the datasheet. I expected simply clicking on its name would give me the datasheet I wanted. But no, it inexplicably requires me to fill out a form rather than just give me the datasheet I clicked on. After I fill out all that information, I expect it to either give me the datasheet directly or perhaps email it to me. But no, it politely requests "Please enter a valid email address." But that email address *is* valid.
  • SeeqPod
  • Shopatron
  • Skype
  • Steam. "Illegal character" !
  • SNCF
  • Sun's site gives this error when I type in my plussed address: "Registration Error: Complete all required fields. Email Address can contain only A-Z a-z 0-9 @ . - _".
  • Sun again, on the registration page ([3])
  • when you register to create a new account: "The email you entered doesn't look like a valid email address. Please check the email address and try creating an account again."
  • As far as I can tell, all sites that use the Tiki Wiki software [4]
  • : it used to accept proper addresses, and use them without problem. Apparently someone with too much time on their hands decided that doing things the right way was wrong: when renewing their subscription, customers are told that their previously OK address contains "illegal" characters.
  • Virgin Money Giving: used to accept plussed addresses, now gives the error "Something went wrong while validating email address. Please try again, and if the problem persists, contact Virgin Money Giving."
  • YouSendIt "Does not appear to be a valid email address"
  • ZDNet Australia (talkback)
  • truck driving jobs
  • Zoosk dating service

Plus Haters: Validation scripts that reject valid addresses

  • SmartWebby rejects addresses containing characters from a list. (Note that the copy/paste script is not what is actually used on that page; view the page's source to see the problem JavaScript.)
  • The JavaScript Source requires user field contain only word characters, dash, and dot
  • Lawrence' email validator limits user field to alphanumerics, underscore, dash, and dot
  • Similar problems, but this one strangely allows ~ and ^
  • XWork Java framework that includes an EmailValidator class with an overly-restrictive regular expression
  • Validate Email Address Format RegEx Does accept + but does not accept a variety of other valid addresses including o', "o'foo", "o\ foo", etc.
  • Advanced Block MOD phpBB bulletin board anti-spam addon that blocks registration with disposable addresses, including addresses with dots as used by Gmail.

Web sites that inexplicably reject other internet standards

Web sites that inexplicably reject other internet standards, and other web sites that complain about them.

Web sites that respect their audience and that, when notified, fixed their forms so as to accept plus addressing

These people understand what standards are about, and are concerned with customer satisfaction. They don't try to bullshit you into changing your email address; they just fix the problem on their side.

  • Made to Order Software Corporation
  • Naymz When the problem was pointed out, Naymz promptly discontinued use of XWork's EmailValidator and switched to the Apache Commons validator, and is now accepting plussed addresses.
  • (Although they're not going to accept some valid addresses, they were very professional when faced with the problem and modified their software so as to accept plus signs.)
  • Wikidot (Although they're not going to accept some valid addresses, when faced with the problem they modified their software to accept plus signs)

Web sites that were listed and fixed their forms for unknown reasons

Web sites that were listed and now may not exist anymore

Sendmail workaround

The following code, added to, will allow the use of dot instead of plus to create the same effect.

dnl # replace user.extra with user+extra for plushater websites that don't allow + in address 
Kplushaters regex -s1,2 -d+ ^([^.@]+)\.(.+)$$ 
R$+ < @ $=w . > $: $(plushaters $1 $: $1 $) < @ $2 . >

A tab character must precede the $: in the last line. This code is based on a comp.mail.sendmail newsgroup post.

More about "plus addressing"