When working with Yahoo email accounts and attempting to upload email messages into your GoldFynch case using our add-on services, it's important to understand the limitations imposed by Yahoo's IMAP server. For more details on requesting add-on services, please refer to this link.
Current limitation: 10,000 Emails per Folder
Yahoo's documentation suggests that folders containing over 100,000 emails may encounter problems while downloading emails via IMAP (see related documentation). Our recent testing has shown that issues can occur with as few as 10,000 emails per folder.
In June 2022, Yahoo changed the behavior of its standard IMAP server (imap.mail.yahoo.com) so that it will only sync or allow you to download the most recent 10,000 messages from any folder. If the folder contains more than 10,000 messages, older emails will simply not be included. This limit was documented by Microsoft and Mozilla support forums, where users noticed that Outlook and Thunderbird would no longer show messages beyond the 10‑k threshold, and Microsoft’s support MVP explained that “Yahoo now has a sync limit of 10,000 messages per folder”
What we are seeing:
We are currently using the imap.mail.yahoo.com server, as it is the only one responding consistently and allowing us to connect and download messages. Unfortunately, this server appears to have a hard limit of 10,000 emails per folder. Messages above that threshold (10.000 emails/folder) in any given folder are not retrievable via IMAP. This behavior is consistent across multiple test accounts and environments.
What about other Yahoo servers?
According to various resources, export.imap.mail.yahoo.com is intended to support larger or full-mailbox exports with a limit of up to 100,000 emails per folder (see related documentation). However, our tests on 5th August 2025 shows that this server is either not functioning well or is severely throttled (we couldn't fetch a single mail from it and it kept booting us).
The export.imap.mail.yahoo.com server is unresponsive and has not allowed us to retrieve any messages at all.
As a result, we are proceeding with imap.mail.yahoo.com as the only viable option.
What you can do
Since this limitation exists on Yahoo’s end and cannot be overridden by GoldFynch, we recommend the following:
Break large folders into smaller ones (preferably with fewer than 10,000 messages each) before initiating the download.
Prioritize folders with fewer messages or those that contain emails most relevant to your matter.
If splitting folders isn’t possible, consider working with Yahoo support directly to explore alternative export options (e.g., Yahoo’s native export tools, if available).
Summary
| Server | Status | Notes |
|---|---|---|
imap.mail.yahoo.com | ✅ Responsive | Limited to ~10,000 messages per folder via IMAP |
export.imap.mail.yahoo.com | ❌ Unresponsive | Cannot connect or retrieve messages during current testing |
We’ll continue to monitor for any changes or improvements from Yahoo's end and will update this article if we discover workarounds or receive confirmation of updated limits.
We have determined through our testing and research on this topic that -
- Yahoo’s IMAP server imposes a hard cap on how many messages it will deliver per folder, not a daily quota.
- The limit applies to the total number of messages that can be retrieved or stored in a single folder via Yahoo’s regular IMAP service.
Way Forward
Based on our prior experience, we have obtained emails of this size before (on a per-folder level, not across multiple folders)
The estimated time taken is around 1-3 hours. Dependent on the size of emails and if there is throttling. Sometimes the connection might drop and it will have to be restarted.
If you need assistance working through this limitation or have questions about folder reorganization, feel free to reach out to GoldFynch Support at support@goldfynch.com