Proton Mail's search function halts after processing a specific volume of messages.
Proton Mail's search function halts after processing a specific volume of messages.
I wrote this after encountering the same problem across all browsers and computers I tried to use. Eventually, I resolved it myself. I first reached out via proton mail support, but after several attempts they lost interest. Over time, I became frustrated without the feature and decided to try again. Here’s what I did: I performed a clean install of Proton Mail, removed all cookies and data, then restarted the search indexing. I recorded the point where it failed—specifically at 19,240 emails. After clearing cookies again, I logged in and checked the search results. I noticed the failure occurred around page 384.8, where there were 19,240 emails. I then reset all cookies and data to restart the process, logging back in. I switched to the "all mail" section and calculated how many emails I could view per page (19,240 ÷ 50 = page 384.8). I selected around 150 emails from the end, as it seemed to download in chunks of 150. After re-downloading, everything worked smoothly on all my devices.
Interesting observations: The download process was very memory-heavy, often exhausting available RAM and slowing the system. On a 16GB machine, reaching 15–20k emails could cause noticeable lag. It might help to limit memory usage or set a cap, so the download doesn’t hog resources and keeps the PC responsive. This issue could be Firefox-specific, but I didn’t test further since it’s now fixed.
Update: Later testing revealed a workaround—enable developer tools and throttle internet speed until RAM usage stayed steady. For Firefox, setting the "DSL" to 2Mbps helped reduce strain, though it slowed downloads. Some failed emails were old "delivered but returned" messages from cold job applications, which might have triggered the problem. I also used Proton Mail alongside Gmail auto-forwards and a private domain, which could have contributed. I figured the emails were being downloaded in reverse order from most recent to oldest, but now it’s working. I’ve shared this with Proton Mail and hope they can assist further.
Resolved, review the revised original message edit. For those seeking answers, check the first post.
Awesome! So um... how exactly did you solve it? Always remember to share how you solved it, otherwise nobody else will be able to reap the benefits of a community forum...