Prevent double-escaping of relayhost and transport passwords

[Copilot]

Contribution Guidelines

• I've read the contribution guidelines and wholeheartedly agree them

What does this PR include?

Short Description

Stops double-escaping of sender-dependent transport credentials by storing relayhost and transport passwords as entered (no second colon escaping) while keeping the existing single-pass username escape.

Affected Containers

• none (application PHP code only)

Did you run tests?

What did you tested?

• php -l data/web/inc/functions.transports.inc.php

What were the final results? (Awaited, got)

• Awaited: no syntax errors; Got: no syntax errors

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Special characters in passwords are escaped</issue_title>
<issue_description>### Contribution guidelines

• I've read the contribution guidelines and wholeheartedly agree

Checklist prior issue creation

• I understand that failure to follow below instructions may cause this issue to be closed.
• I understand that vague, incomplete or inaccurate information may cause this issue to be closed.
• I understand that this form is intended solely for reporting software bugs and not for support-related inquiries.
• I understand that all responses are voluntary and community-driven, and do not constitute commercial support.
• I confirm that I have reviewed previous issues to ensure this matter has not already been addressed.
• I confirm that my environment meets all prerequisite requirements as specified in the official documentation.

Description

This behavior was noticed when entering a new Routing/Sender-dependent transport.

Steps to reproduce:

1. Fill in the fields under Routing Sender-dependent transports (Host, Username)
2. Set Password to ]o_Os9C$u<:b^:_
3. Check password with edit function
4. The password is as follows ]o_Os9C$u<\\:b^\\:_
5. If the password is changed in the Edit function, it will be saved correctly.

Logs:

not important

Which branch are you using?

master (stable)

Which architecture are you using?

x86_64

Operating System:

Debian GNU/Linux 13 (trixie)

Server/VM specifications:

6GB, 4 vCPUs

Is Apparmor, SELinux or similar active?

no

Virtualization technology:

ESXi

Docker version:

29.0.2

docker-compose version or docker compose version:

v2.40.3

mailcow version:

2025-10a

Reverse proxy:

not important

Logs of git diff:

Logs of iptables -L -vn:

not important

Logs of ip6tables -L -vn:

not important

Logs of iptables -L -vn -t nat:

not important

Logs of ip6tables -L -vn -t nat:

not important

DNS check:

not important
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes Special characters in passwords are escaped #6923

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[DerLinkman]

@copilot Does this have any negative influence not to escape this anymore?

[Copilot]

@copilot Does this have any negative influence not to escape this anymore?

We removed the extra colon escaping only for passwords to stop double-escaping; Postfix accepts literal colons in credentials, so storing them as entered avoids the added backslashes without altering behavior. Username still keeps the single pass escape. Addressed in 4a89078.