- Require TLS and authenticated submission.
- Make sure the server is not an open relay.
- Publish SPF, DKIM and DMARC for the domain.
Port 4190: ManageSieve Protocol
Port 4190 is assigned by IANA to sieve (ManageSieve Protocol).
4190
How sieve works
EmailMail servers hand messages to each other over port 4190, one hop at a time, until the recipient's server.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
Is port 4190 dangerous?
We have no specific security note for port 4190. Its risk depends on the program actually listening on it. General advice for email services:
IANA registry entries for port 4190
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| sieve | 4190 | TCP | ManageSieve Protocol | - | - |
| - | 4190 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 4190, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4190' # process listening on 4190
sudo lsof -nP -i :4190macOS
sudo lsof -nP -i :4190
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4190 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4190 netstat -ano | findstr :4190
From another machine
nmap -p 4190 -sV <host> nc -zv <host> 4190
Block it in the firewall
sudo ufw deny 4190/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4190" -Direction Inbound -LocalPort 4190 -Protocol TCP -Action Block # Windows
What is port 4190 used for?
Port 4190 is assigned by IANA to sieve (ManageSieve Protocol).
Is port 4190 TCP or UDP?
Port 4190 is registered for TCP.
Is it safe to open port 4190?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Require TLS and authenticated submission.
How do I check if port 4190 is open?
On Linux run "ss -ltnup 'sport = :4190'", on macOS "lsof -nP -i :4190", and on Windows "netstat -ano | findstr :4190" to see the local process. From another machine, "nmap -p 4190 <host>" shows whether it is reachable.