Does a capital letter in an email address change it?

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Stephyfr Posted messages 84 Status Member -  
PascalKOTTE Posted messages 3 Status Member -
Hello,

For entering an internet address, does using uppercase
or lowercase letters in a person's name have any impact?

If my address is quidam.personne@wanadoo.fr and someone types
Quidam.Personne@xanadoo.fr, does it change anything?

For a company email, can the administrator who assigns addresses decide that the first letter of the first and last names must be uppercase, otherwise the address is considered invalid (in the paragraph above only the second address would be valid, if someone writes to the first one, will there be a failure return)?

Does this have to do with ASCII code?

Thank you for the responses and have a good end of the year.

Stephy

3 answers

  1. ipl Posted messages 5738 Status Security Contributor 585
     
    Hello Stephyfr, hello everyone,

    Based on my experience, it doesn't matter whether you use uppercase or lowercase letters in an email address, but some sites check that the domain (after the @) respects the case. As a precaution, it is customary for email addresses to be written in lowercase.

    quidam.personne@wanadoo.fr & Quidam.Personne@wanadoo.fr are equivalent (as are QUIDAM.PERSONNE@wanadoo.fr)!

    @12C4
    Ipl
    115
    1. Joulaye
       
      Thank you for the info!!
      0
    2. PascalKOTTE Posted messages 3 Status Member 3
       
      In fact, yes and no!
      It will depend on the behavior of the SMTP server that manages the emails of the concerned domain @ledomaine.truc
      https://en.wikipedia.org/wiki/Email_address
      RFC 5321 recommends, but does not require, that "local" names be 'case insensitive' (insensitive to upper/lower case) and as is widely practiced, it’s the same, upper or lower...
      But the server does as it pleases. Therefore, there could be emails differentiated between upper and lower case...
      See https://en.wikipedia.org/wiki/Email_address

      A bit like Google with Gmail, which removes '.' (dots) regardless of their presence or absence
      thus machin.truc@gmail.com will work the same as machintruc@gmail.com or ma.chin.tr.uc@gmail.com

      That's specific to Google... Others generally don't do that...
      So it's not always true, but it's often the case!

      Ah, computing, something meant to be binary!
      https://pkotte.medium.com/auto-portrait-3f6d80101e49
      3