Comment 155 for bug 275471

(In reply to comment #146)
> rsx11m - ah a 4MB limit! Well that explains my behaviour but my findings

That's the previous limit of the *memory* cache, which caused issues in the past. The disk cache has a default limit of 50MB, and as David just stated, the offline store doesn't have any pre-set limit. It only goes into effect though if and when the message and/or its attachments are actually synchronized, until then you have to rely on the disk and/or memory cache (which, as stated, is somewhat broken).