MULE-7837: Added offset and limit parameter to email retrieving process. Added tests for the delete/no delete options when retrieving them.
(cherry picked from commit 0301cea4abe40e99775f133ab5133eb326c4dd1f)
MULE-7837: Comments added to make logic clearer, constants added to test case, all according to PR comments.
(cherry picked from commit 2b2ff49be87b95b79a91636f9ec36dab2727bab7)