ProtonMail/gluon

An IMAP server library written in Go

Go

555

632 commits

updated Oct 9, 2026

See the code

README

Gluon

An IMAP4rev1 library focusing on correctness, stability and performance.

CI Status GoDoc Go Report Card License

Demo

The demo server can be started with:

$ GLUON_LOG_LEVEL=trace go run demo/demo.go
DEBU[0000] Applying update                               update="MailboxCreated: Mailbox.ID = 0, Mailbox.Name = INBOX" user-id=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
DEBU[0000] Applying update                               update="MessagesCreated: MessageCount=0 Messages=[]" user-id=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
INFO[0000] User added to server                          userID=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
DEBU[0000] Applying update                               update="MailboxCreated: Mailbox.ID = 0, Mailbox.Name = INBOX" user-id=a51fad46-9bde-462a-a467-6c30f9a40a63
DEBU[0000] Applying update                               update="MessagesCreated: MessageCount=0 Messages=[]" user-id=a51fad46-9bde-462a-a467-6c30f9a40a63
INFO[0000] User added to server                          userID=a51fad46-9bde-462a-a467-6c30f9a40a63
INFO[0000] Server is listening on 127.0.0.1:1143

By default, the demo server includes two demo users, both with password pass. The first has addresses user1@example.com and alias1@example.com. The second has addresses user2@example.com and alias2@example.com.

Once started, connect to the demo server with an email client (e.g. thunderbird) or via telnet:

$ telnet 127.0.0.1 1143
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IDLE IMAP4rev1 MOVE UIDPLUS UNSELECT]  00.00.00 - gluon session ID 2
tag login user1@example.com pass
tag OK [CAPABILITY IDLE IMAP4rev1 MOVE UIDPLUS UNSELECT] Logged in
tag append inbox (\Seen) {14}
+ Ready
To: user@pm.me
tag OK [APPENDUID 1 1] APPEND
tag select inbox
* FLAGS (\Answered \Deleted \Flagged \Seen)
* 1 EXISTS
* 1 RECENT
* OK [PERMANENTFLAGS (\Answered \Deleted \Flagged \Seen)] Flags permitted
* OK [UIDNEXT 2] Predicted next UID
* OK [UIDVALIDITY 1] UIDs valid
tag OK [READ-WRITE] SELECT
tag fetch 1:* (UID BODY.PEEK[])
* 1 FETCH (UID 1 BODY[] {32}
X-Pm-Gluon-Id: 1
To: user@pm.me)
tag OK command completed in 1.030958ms

Changing DB schema

Do not forget to re-generate ent code after changing the DB schema in ./internal/db/ent/schema.

pushd ./internal/db/ent && go generate . && popd

go
golang
imap
imap4
imaplib
imap-server
proton
protonmail

Project health

Latest release

v0.17.0 · Jul 7, 2023

Releases this year

0

Significant stargazers

Yagiz Nizipli

2,346 followers · starred Feb 2023

Syrus Akbary

1,254 followers · starred Feb 2023

Tai Groot

359 followers · starred Jul 2023

Nick Cao

570 followers · starred Feb 2023

ProtonMail/gluon

An IMAP server library written in Go

Go

555

632 commits

updated Oct 9, 2026

See the code

README

Gluon

An IMAP4rev1 library focusing on correctness, stability and performance.

CI Status GoDoc Go Report Card License

Demo

The demo server can be started with:

$ GLUON_LOG_LEVEL=trace go run demo/demo.go
DEBU[0000] Applying update                               update="MailboxCreated: Mailbox.ID = 0, Mailbox.Name = INBOX" user-id=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
DEBU[0000] Applying update                               update="MessagesCreated: MessageCount=0 Messages=[]" user-id=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
INFO[0000] User added to server                          userID=ac8970c5-cdb7-4043-ad85-ad9b9defcfb8
DEBU[0000] Applying update                               update="MailboxCreated: Mailbox.ID = 0, Mailbox.Name = INBOX" user-id=a51fad46-9bde-462a-a467-6c30f9a40a63
DEBU[0000] Applying update                               update="MessagesCreated: MessageCount=0 Messages=[]" user-id=a51fad46-9bde-462a-a467-6c30f9a40a63
INFO[0000] User added to server                          userID=a51fad46-9bde-462a-a467-6c30f9a40a63
INFO[0000] Server is listening on 127.0.0.1:1143

By default, the demo server includes two demo users, both with password pass. The first has addresses user1@example.com and alias1@example.com. The second has addresses user2@example.com and alias2@example.com.

Once started, connect to the demo server with an email client (e.g. thunderbird) or via telnet:

$ telnet 127.0.0.1 1143
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IDLE IMAP4rev1 MOVE UIDPLUS UNSELECT]  00.00.00 - gluon session ID 2
tag login user1@example.com pass
tag OK [CAPABILITY IDLE IMAP4rev1 MOVE UIDPLUS UNSELECT] Logged in
tag append inbox (\Seen) {14}
+ Ready
To: user@pm.me
tag OK [APPENDUID 1 1] APPEND
tag select inbox
* FLAGS (\Answered \Deleted \Flagged \Seen)
* 1 EXISTS
* 1 RECENT
* OK [PERMANENTFLAGS (\Answered \Deleted \Flagged \Seen)] Flags permitted
* OK [UIDNEXT 2] Predicted next UID
* OK [UIDVALIDITY 1] UIDs valid
tag OK [READ-WRITE] SELECT
tag fetch 1:* (UID BODY.PEEK[])
* 1 FETCH (UID 1 BODY[] {32}
X-Pm-Gluon-Id: 1
To: user@pm.me)
tag OK command completed in 1.030958ms

Changing DB schema

Do not forget to re-generate ent code after changing the DB schema in ./internal/db/ent/schema.

pushd ./internal/db/ent && go generate . && popd

go
golang
imap
imap4
imaplib
imap-server
proton
protonmail

Project health

Latest release

v0.17.0 · Jul 7, 2023

Releases this year

0

Significant stargazers

Yagiz Nizipli

2,346 followers · starred Feb 2023

Syrus Akbary

1,254 followers · starred Feb 2023

Tai Groot

359 followers · starred Jul 2023

Nick Cao

570 followers · starred Feb 2023