Change / Migrate Email Hosting to Hosting Company SITEGROUND .

I have hosting package with HeartInternet with email data hosted.
Website hosting is not existing there.
I am moving to new hosting company https://www.siteground.co.uk/

I have one domain that I use for my biz emails. On that domain we have one main email FDS@ and 2 other emails (info@ and admin@) on same domain that are not used.

Our hosting company IP address is blacklisted so emails send facility is not working as normal. HeartInternet are not attempting to lift this blacklist any time soon. The account was previously affected by malware and domain was blacklisted. The domain blacklist has now been lifted.

As I see it, the solution to get emails working is to move hosting company to SITEGROUND.CO.UK.

The email data should be copied over to new server and re-establish working emails and tested. SITEGROUND does not have cpanel interface instead has its own "SITE TOOLS" as described via link below;
https://www.siteground.co.uk/blog/new-client-area-and-site-tools/

And step by step tutorials for migration using 3rd party such as Thunderbird or other;
https://www.siteground.com/kb/transfer-emails-imap-between-servers/

Task is to transfer 1 email of about 1GB of data in FDS@ / approx. 30-40 folders in total.
Will need to take back up of email data first.
The other emails have very little data if any at all so no need to migrate that data.

I need an experienced skilled developer with excellent conduct and great communication.

Will require Skype interview before proceeding.
Thanks!