Can 2 people in different locations at the same time import, access, send, and receive the same messages from the same email account

Question

I import messages into Thunderbird. I send and receive emails. One of the things I like about Thunderbird is that I can insert (image, link, etc) right where I want to, and I can Attach. But not just a simple attach file. No, I can also click Attach and choose Webpage. A lot of web-based emails are plain, simple, no frills - Attach file and that's it.
So I need to have my client be able to do the same thing I do when sending out emails, Namely sending out emails with an Electronic Press Kit (EPK) attached - which is to say, a webpage (not a pdf in our case). So, I need her to download, install, and use Thunderbird.
Here's the problem and my question. She needs to access, send, and receive from my email account. That would be easy if it was simple attach files - she could just login on the web, go to squirrel mail and bang it out.. Here it is: She needs to be able to import the messages to be able to reply to some messages - she needs access to what I have access to. She needs to use Thunderbird so she can take advantage of the features like insert image with link or attaching a webpage. My question is how will this affect my use? Can 2 people simultaneously and from different locations access and use the same email account or is it a case where her importing the emails would cut me off..Is it an either or thing? Basically, can her and I both import the emails or can they only be imported to one location at a time. Because every time someone sends me an email i get it right there on my Thunderbird application..it's imported to my Thunderbird..I want her and I to be able to do that without affecting each other. I don't want her to start importing to her desktop and then I can no longer import. If she says "point those messages to my computer what will happen to my ability to access them on my computer in the same manner I am currently?

Answer 1

I think there is a contradiction in your requirements. You want two people to share an account and you don't want either to interfere with the other.
The short and simple answer is to use IMAP to connect to the mail server. If your current email provider doesn't offer IMAP, find another that does. This is old technology already and it's disgraceful that some email providers haven't yet put it in place.
IMAP means that your messages are stored on the server and both of you will see exactly the same set of messages. And therein lies the contradiction; you will both see changes made by the other so you are inherently interfering with one another.
Caveats: some providers may not permit you both to access the account concurrently, and even if they do, things may become interesting if you both choose to work on the same message simultaneously.
Note that all of this is about email servers and protocols; your choice of Thunderbird as your email client has little bearing on the situation.