[horde] Improving ActiveSync speed on large mailboxes

[Sebastian Arcus]

On 14/07/2026 17:47, Nels Lindquist wrote:
> On 2026-07-14 9:32 AM, Sebastian Arcus wrote:
>> On 14/07/2026 15:40, Nels Lindquist wrote:
>>> Hi, Sebastian.
>>>
>>> On 2026-07-13 9:41 AM, Sebastian Arcus wrote:
> 
> <SNIP>
> 
>>> Do you have imap caching enabled in imp? If so, what cache driver are 
>>> you using?
>>>
>>> Is there a reason you need to have entire mailboxes with all 
>>> historical mail loaded on mobile devices? It's pretty typical for the 
>>> client to only download the last 30 days worth of messages, with 
>>> remote search available to access older messages on demand.
>>
>> I configure mobile clients to only download 1 month worth of emails. 
>> These are very busy mailboxes, and although it works, it is very slow 
>> to load the initial list in Gmail and generally to configure and use. 
>> A significant reason behind this is that Gmail requests a lot of data. 
>> Looking at the logs, iOS Mail app seems to request 500 byes per 
>> message, while Gmail requests 200 000. That is 40 times more data. The 
>> iOS Mail app is far faster to load the list and generally to work with 
>> email using ActiveSync. Even searches use the same truncation 
>> parameter, so returning search results is much slower in Gmail (aside 
>> from the fact that Gmail insists on searching all folders - but that's 
>> an issue to be tackled separately). If Horde would have something like 
>> ['activesync'] ['force_truncation_size'] to override the client and 
>> return 500 byes (or some other size configurable by the admin) per 
>> message when talking to the Gmail app, like in the case of iOS Mail, 
>> Gmail should be significantly more responsive and efficient.
> 
> How about the imap caching?

Yes - that is enabled with the 'hashtable' setting. I've configured both 
the Gmail app (on Android) and the iOS Mail app against the same email 
account on the same Horde 6 install - and the performance difference is 
night and day. Before I finished setting up the account in Mail, the 
inbox was already populated with the default 1 month worth of emails. In 
Gmail, I have to wait around for a good while for it to download even 
the default 1 week. Admittedly, as mentioned previously, this is a 
really busy mailbox. Also the hardware on the two mobile phones is 
completely different - which might or might not have some impact on 
performance.