如何代表来自不同域的其他人发送 email

Question

I am building an e-commerce website (let's call it e-buy.com). What I want is a mailing system where buyer can send an email to seller... so for example, I would have to send an email like this:

from: buyer1@yahoo.com
to: seller1@gmail.com
subject: buyer inquiry via e-buy.com

I have built the above solution, but sometimes my emails are not delivered... the reason (as far as I know) is that I am sending an email from: e-buy.com domain but the sender is from a different domain: buyer1@yahoo.com

Question 1> Is this a bad practice to set the from field to a domain different from the mail server's domain?

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I have seen some websites implement the following solution in the same situation:

from: mailer@e-buy.com
to: seller1@gmail.com
subject: buyer inquiry via e-buy.com e-commerce 

So email is coming from: mailer@e-buy.com , but when the seller clicks on reply button, the reply automatically changes from mailer@e-buy.com to buyer1@yahoo.com

Question 2> How can this switching of sender's email be implemented?

Answer 1

Answer 1: When sending emails from another domain - you need to keep in mind that they will need to setup DNS records to list your mail server / sender as a legitimate email sender, seeming as you'll most likely have multiple big brand domains (gmail, yahoo, hotmail, etc), this approach is most likely not what you want.

Answer 2: This is more realistic and quite easy to implement. What you're looking for is a reply-to header. This will specify what email users should be sending to when they try to reply to an email.

Explained further here .

When you send an email to a subscriber and they click 'Reply', the reply message is typically sent to the email address listed in the From: header.

A Reply-To address is identified by inserting the Reply-To header in your email. It is the email address that the reply message is sent when you want the reply to go to an email address that is different than the From: address.

In the example below, 'service@sampledomain.com' is the Reply-To address. When a subscriber clicks 'Reply', the reply message is sent to 'service@sampledomain.com' instead of 'marketing@sampledomain.com'.

From: marketing@sampledomain.com

to: aaasample@zzzexample.com