Port 4190ManageSieve

ManageSieve lets mail clients and administrators upload, activate, and manage Sieve filtering scripts.

transport: tcp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

also known as RFC 5804

Technical Details

what runs on :4190

ManageSieve is a line-oriented TCP protocol defined in RFC 5804 for managing Sieve scripts, the mail-filtering language defined in RFC 5228. A server sends an initial greeting and capability information; clients authenticate using SASL, then issue commands such as LISTSCRIPTS, GETSCRIPT, PUTSCRIPT, SETACTIVE, DELETESCRIPT, and LOGOUT. Script content is transferred using protocol literals, and STARTTLS can upgrade the connection to TLS. TCP 4190 is the standard ManageSieve port; encryption is not implicit by default.

Security Information

exposure of :4190

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

email averages 3.3 across 56 ports — this one sits 2.7 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

An exposed service can be targeted for password guessing and abuse of authenticated accounts to alter filtering rules, redirect mail, delete messages, or exfiltrate content. Because credentials and scripts are cleartext before TLS negotiation, deployments should require and correctly validate TLS, enforce strong authentication, rate-limit login attempts, and restrict access to trusted networks where possible.

Record

iana registry entry

port: :4190
service: ManageSieve
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: Email Network Services
usage: Mail clients and administration tools use TCP 4190 to manage server-side Sieve scripts for mail filtering. It is commonly provided by mail platforms such as Dovecot and Cyrus alongside IMAP and SMTP services.
lookups: 0rank 994
added: 2026-09-13
updated: 2026-09-13
references: IANA service name registry — port 4190

Something wrong?

This record is maintained by the engineers who use port 4190. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-13.

01edit any field on a page of its own
02a model checks it for accuracy and spam
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edit this record →back to the registry

Related Ports

all 56 in email →

the 8 most looked-up other ports in email — 56 ports carry that label.

port	service	proto	category	risk	views
:143	IMAP	TCPUDP	Email	caution	20.7k
:995	POP3S	TCPtls	Email	caution	18.8k
:109	POP2	TCP	Email	caution	17.9k
:2096	cPanel SSL Webmail	TCPtls	Web Services	safe	17.4k
:110	POP3	TCP	Email	caution	15.5k
:993	IMAPS	TCPtls	Email	caution	14.5k
:1352	Lotus Notes RPC	TCP	Email	caution	12.3k
:24	Private Mail	TCPUDP	Email	caution	11.7k

risk mix of the 8 listed

safe13%
caution88%

3 of 8 encrypted

Port :4190ManageSieve

Technical Details

Security Information

Related Ports

Port 4190ManageSieve