Nextcloud Mail causes extreme memory usage and freezes browser tab on initial load
Nobody has claimed this yet.
- Dominant language
- JavaScript
- Stars
- 1k
- Forks
- 348
- Avg merge
- 12h 28m
- Merged PRs (30d)
- 91
Description
Steps to reproduce
When I open the Nextcloud Mail app, memory usage rapidly increases until the browser consumes most or all available RAM. The Mail tab then becomes unresponsive.
This has been happening consistently for approximately six months and has persisted across multiple Nextcloud/Nextcloud Mail updates.
I initially observed it in Zen Browser (Firefox-based), but I have now reproduced the same behavior in Microsoft Edge (Chromium-based) as well. This suggests the issue is likely not specific to a particular browser engine.
- Open Nextcloud.
- Navigate to the Mail app.
- Wait for the initial mailbox loading/synchronization.
- Observe browser/system memory usage.
- Memory usage grows significantly and the Mail tab eventually becomes unresponsive.
Expected behavior
Nextcloud Mail should load and synchronize without continuously increasing memory usage or causing the browser tab to freeze.
Actual behavior
During the initial loading/synchronization of Nextcloud Mail, memory usage increases dramatically.
In Zen Browser, I observed approximately 7.4 GB RAM usage, with overall system memory usage reaching 98%, after which the tab became unresponsive.
I have now reproduced the same unresponsive behavior in Microsoft Edge, where Edge displays the browser's “This page isn’t responding” dialog for the Nextcloud Mail tab.
Mail app version
5.12.0
Nextcloud version
34.0.1
Mailserver or service
No response
Operating system
No response
PHP engine version
No response
Nextcloud memory caching
No response
Web server
No response
Database
No response
Additional info
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
No source file or test is named. First reproduce the initial Nextcloud Mail load and synchronization in a supported browser, then trace the client-side loading path while monitoring memory growth. Done means the initial mailbox load completes without continuous memory growth or an unresponsive tab in both Firefox-based and Chromium-based browsers.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- frontend, performance
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Active
- Clarity
- Needs clarification
- Newbie friendliness
- 38/100