Issue Description Sub-Adressing should work when enabled for the domain, but since 0.16.x (after upgrade from 0.15) sub-adressing doesn’t seem to work anymore Expected Behavior mark+xxx@domain should be delivered to the existing account mark@domain Actual Behavior 5.5.0, Message: Mailbox not found…

This has been fixed on the main branch. The fix will be included in v0.16.8.

Let me research the subaddressing configuration for Stalwart, particularly any changes between 0.15 and 0.16. Based on what I found, here is a focused answer. In the current architecture, subaddressing is configured per Domain object via the subAddressing field. After upgrading from 0.15, this fie…

I already checked this, it is set to “Enabled”. Normal e-mail receiving works, and also I can login as mark@domain. So I assume that LDAP is correctly setup. I added mark+XXX@domain as a temporary test as an alias for mark@domain - that works, but that isn’t a solution.

The plus-strip happens upstream of the directory; LDAP itself never sees the “+” because Stalwart strips it before the recipient lookup. That strip is gated on a per-domain flag built from the registry’s SubAddressing field at domain-cache build time, and the SubAddressing enum picked up @type ta…

Thanks for getting back to me! I did: Upgrade to 0.16.7 (that is also a server restart I guess :smiley: ) Check with CLI: {"name":"DOMAIN","aliases":{},"isEnabled":true,"createdAt":"2026-05-11T08:02:46Z","description":"DOMAIN","logo":null,"certificateManagement":{"@type":"Manual"},"dkimManagemen…

I have the same issue. Normal delivery works like a charm, but using subaddressing breaks. I’m also using an ldap directoy. For now I’ve restored the backup, since I use subaddressing a lot.

@stalwart Would trace logs from @Kidswiss and @palight help? @Kidswiss / @palight Could you maybe provide TRACE logs for a mail receive event where sub-addressing is not correctly followed? (Maybe difficult for @Kidswiss if you have only one env and already downgraded)

Hi, I tried tonight with trace logs. Problem seems to be that with external directories, server first cache aliases from external directory and then when an email inbound, it look in cache entries if full recipient exists, no more obfuscating subaddress. So it can’t find user+test in cache and don…

I can confirm that it works for my case now! Thank you very much!

Hello, Firstly, Thank you so much for Stalwart. We are trialing the Enterprise version and so far, love what we see. I am however, also having this issue with sub-addressing. Sub addressing for domain is definitely on we are using a local directory for our testing we have version 0.16.8 install…

SubAdressing no longer seems to work after upgrade to 0.16

Issues

palight June 2, 2026, 5:32am 7

Hello, I got the same problem with SQL directory (Subaddress and sql directory - #17 by palight).

Maybe a bug with subadressing and external directories?

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SubAdressing no longer seems to work after upgrade to 0.16

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