Improve performance

If SnappyMail feels very slow or sluggish we need to find out why that is. Using the full debug mode and analyzing the log, you may find the issue and probably a solution.

First turn on debugging and Login

1. Go to Admin -> Config and find the option debug and turn it on. Then at the bottom hit the Save button.
2. Open a new browser tab and login with an email account.
3. When fully loaded go back to Admin and turn off the debug mode to prevent noise of other logging.

Analyzing the log

Open the log at _data_/_default_/logs/*.txt and we will walk you through the process.

Setup connection speed

IMAP[INFO]: Start connection to "tcp://localhost:143"
IMAP[DEBUG]: 0.00046396255493164 (raw connection)

This is the time it took to make a connection with the server.

IMAP[INFO]: < * OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ STARTTLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready.\r\n
IMAP[DEBUG]: 0.0017571449279785 (*)

This is the time it took to the connection and get the first response from the server. If the response doesn't have [CAPABILITY, the next question to the server is IMAP[INFO]: > TAG CAPABILITY\r\n to get all capabilities.

Requests speed

Now the connection is fully set and we go ask the server to STARTTLS or AUTHENTICATE.

IMAP[INFO]: > TAG AUTHENTICATE PLAIN Base64==\r\n
IMAP[DEBUG]: 0.27842593193054 (TAG)

This is the time it took to login on the server.

Now each additional request is the same way:

IMAP[INFO]: > TAG ....\r\n
IMAP[INFO]: < ...\r\n
IMAP[DEBUG]: 0.27842593193054 (TAG)

Finished total speed

And finally it ends with the LOGOUT and the total time it took.

IMAP[INFO]: Disconnected from "tcp://localhost:143" (success)
IMAP[DEBUG]: 0.28226494789123454 (net session)

Things that could speed up your instance and prevent timeouts

IMAP Proxy

Dovecot allows you to keep remote connections alive by proxying https://doc.dovecot.org/admin_manual/dovecot_proxy/

Disable capabilities

How to can be found at: https://github.com/the-djmaze/snappymail/wiki/IMAP-capabilities

Disable folders LIST-STATUS

1. Go to Admin -> Domains -> "the domain"
2. In the Disable capabilities section check LIST-STATUS
3. Hit the save button at the bottom

RFC 5819 LIST-STATUS is a way to return a lot of info instantly from the IMAP server. This way SnappyMail only has to do 1 request to the IMAP server to fetch all required information of all folders. When the IMAP server is slow (for whatever reason) this kind of request can take a very long time. With the above setting you disable the feature and SnappyMail has to do several requests on the background (depends on the amount of folders).

Disable folders METADATA

1. Go to Admin -> Domains -> "the domain"
2. In the Disable capabilities section check METADATA
3. Hit the save button at the bottom

The folders METADATA is fetched to support RFC 5464, RFC 6154 and Kolab. With the above setting you disable the feature and SnappyMail has no support to check for comments nor special-use nor integrate with Kolab.

Disable folders STATUS SIZE

1. Go to Admin -> Domains -> "the domain"
2. In the Disable capabilities section check STATUS SIZE
3. Hit the save button at the bottom

With STATUS SIZE each folder size is calculated by the IMAP software and shown in the Settings -> Folders section

Also read https://github.com/the-djmaze/snappymail/issues/1303

Disable messages SORT(ing)

1. Go to Admin -> Domains -> "the domain"
2. In the Disable capabilities section check SORT
3. Hit the save button at the bottom

Sorting relies on the smart capabilities of the IMAP software. When it is slow, this speeds things up, but does disable the sorting features. Messages will probably be shown based on receival so when an old message is received it will be shown as first and the list could be a big mess.

Read more at https://github.com/the-djmaze/snappymail/issues/1022

Disable messages THREAD(ed) view

1. Go to Admin -> Domains -> "the domain"
2. In the Disable capabilities section check THREAD
3. Hit the save button at the bottom

When fetching the messages list SnappyMail can combine messages in a thread. This relies on the smart capabilities of the IMAP software. When it is slow, this speeds things up, but does disable the threaded view features.

Shorten messages list

1. Go to Admin -> Domains -> "the domain"
2. In the Limits section set Messages to an amount you prefer (say 1000)
3. Hit the save button at the bottom

When there are more then N messages (say 1000) the system will not fetch all messages uid's for sorting. It will only fetch a subset to speed things up.

Also read issues

• https://github.com/the-djmaze/snappymail/issues/724
• https://github.com/the-djmaze/snappymail/issues/1071

Dovecot

You can speed this up using ElasticSearch https://github.com/filiphanes/fts-elastic