I run Thunderbird, Thunderbird ESR, K-9 or Thunderbird. Windows 7, 10 and 11, Linux and Android 5.1 and 12. My desktops all have a gmail and yahoo.co.uk email addresses. Each account is linked to there respective contacts server but all my contacts are in one gmail account which has lost most of the contacts in recent months, that is, only the contacts that I have used recently are still present. So I have been investigating the settings and adjusting in some cases. Some instances all the account are still linked to the contacts servers. Other cases only some of the accounts are still linked and I want to re-establish the other accounts that have become local accounts, these still have my full complete address book. Lastly between K9, thunderbird, contacts google I don't know what went wrong but I like advice on how to avoid the problem in future. In the meantime seasons greatings, no hurry my christmas messages will have to wait.