There is no official Mozilla one-on-one support or paid support for Thunderbird. The people in this "community forum" helping with Thunderbird are all unpaid volunteers. Any one-on-one and/or paid support you can get for Thunderbird would be outside the purview of this forum and Mozilla. Mozilla does not charge for downloads, upgrades or technical support, and does not endorse any company that does. Individuals here might offer the support you are looking for, but it might be difficult to find someone willing to do so for free. '''So your choice now''' is to either ask your questions here that we will do our best to answer, or find someone who can provide the one-on-one support you want.