gmail addresses are not case sensitive, meaning the email service doesnt distinguish between versions of the address with or without capitalized letters, so long as the spelling is the same.
If you have a capital letter in your email idaddress, then lets say if you type your id all in small letters in any social networking. I would suggest using different techniques in the capitalization of the letters for different points you are trying to get across.
the domain name in an email address is case-insensitive, meaning it doesnt matter whether you use upper or lower case. The same applies to usernames, though outdated email servers can misinterpret capitalization in rare cases. For simplicitys sake, the best practice is to use only lower-case letters in a username.
Though google will usually display an email address as all lowercase.
You can type an email address using capital letters but it wont matter. Nowadays email providers and email clients will automatically correct case sensitivities. For example when typing an email on mailbird, gmail, or outlook, these email clients will automatically convert email addresses to all lowercase letters when sending the email.
you can capitalize all the letters in the first part of the email address and it will still get to the same person. And yes, smartphones will always capitalize the first letter of a sentence.
Gmail also doesnt make a distinction between lowercase and capital letters in addresses.
Answer capital letters dont matter in email addresses thisemailsupercrazylongwebsiteaddress. So you can send it to either with no problems, but you may notice that one is easier to read than the other.
My dad says capitals used to matter (years ago) for email addresses but dont anymore. Im fairly sure they never did because something like that involving dnsmx changes would not change.