Hi!

We have a single mailbox, but have multiple distribution list with different names like abc@domain.com, bcd@domain.com, but these are having single mailbox, can we use as separate emails in Pegasus mail, if yes can someone guide how?

I am doing that with no problem. I have 3 identities. The only issue is you have one default and the other ids can have there own setups from downloading and sending email. Generally, I have flagged the default ident to download mail and send mail in a single operation. You may or may not want to do that.
I generally filter mail into folders based on the identify. Also, might want to link folders to specific identities, and that way went you reply to messages in those folders, it will use the identity linked to that folder, and it will also use that identities setup for sending. Especially useful if that identity is the only one authorized to send to lists or email addresses.

If you have setup multiple users, you just create short cuts the -I user.
I don't use that, but have a test setup that has three users the Admin, Jack and Jill.
That has separate mail directories for each user with there own folders. It does require exiting and restarting Pegasus.
Think the is an -MS switch that allows for running more than 1 instance of Pegasus, but I've never tried that?

Hope that helps. Sure if I've said anything wrong or left something out, others will add info here.

@msetzerii is correct that creating multiple Identities in Pegasus Mail is probably the best way to accomplish what you want. Each Identity has it own configuration allowing each one to have its own email address, appearance, sending, receiving host configurations, and almost every other configurable option.

You can change Identities at will within Pegasus Mail.

You can assign an Identity to a folder. This is beneficial in that whenever you reply to a message in that folder, it will be sent as that Identity

To work with Identities you use Tools > Identities. This is where you add and delete them. You can also switch Identities by using the "Become" button here. There is also an Identity selector in the main Pegasus Mail window toolbar, making Identity switching more convenient. There is also an option to add an Identity selector to the message composition window which allows you to select the Identity that you want to send that message as.

I suggest reading Chapter 14: Multiple Identities in the Pegasus Mail manual. This may help with the concept of "Identities" if you need it.