Re: Twenty-five years of...
There are people using Outlook that can use it year in, year out, without problem. It's when the user happens to trigger one of the design flaws of Outlook is when the troubles begin. Going "oversize" was the most obvious of those triggers, but MS have now raised that bar, making it statistically less likely.
MS use the "foie gras" technique of storing messages in the repository. Only after the message has been stored is the user made aware that the message store has gone over size and special tools need to be applied to it in order for it to resume working - tools (provided by MS in lieu of a means to prevent the problem happening in the first instance) which can result in loss of data. Other mail clients check boundary conditions *before* inserting messages into the message repository.
Well-meaning malware-checkers can also interfere with Outlook's mode of operation. To ensure Outlook doesn't do anything naughty malware checkers monitor Outlook so tightly that loss of messages and freezing are common-place.
Though this isn't Outlook's fault per se, it is because of such things as the capability Outlook has of being able to be "driven" by third-party apps that cause malware checkers deep distrust of Outlook.
So by all means use Outlook, but complacency is bad: take regular backups of your PST's, and keep the PST size small.
Biting the hand that feeds IT
