gmail
I've been getting this yellow underline frequently, and was wondering what it meant.
A quick Google search revealed to me that:
"The yellow underline means that an address is not inside your domain."
What does this mean, and if I send them emails, do they receive them?
Additionally, can they reply to me?
Yes
In your Gmail settings, under "Accounts and Import", if you have multiple "send mail as" accounts set up you can choose to always default to your Gmail account or to respond with the account to which the message was sent.
RFC2822 says Date: and From: headers are required (section 3.6). It looks like Google will let you get away with just adding a From: header though, e.g.:
[..]
DATA
354 go ahead
From: <account@OurISP.net> <-- add this
Subject: Test email from the Avid ISIS Notification Application This message was generated by Avid ISIS Notification Application.
.
QUIT
250 ok: Message 716893804 accepted
Best Answer
Your domain is the part of your email address after the
@sign.Emails you send "outside your domain" are no different from any other message: the other person will receive the email and can reply to you just like any other email.
The reason for the yellow color is just to make sure you're aware that you're sending a message to someone who may be outside your company or organization.