You get a bonus - 1 coin for daily activity. Now you have 1 coin

Checking the IMAP protocol on a mail server via telnet

Practice



Task: check the functionality of an IMAP server at a low level, by yourself, without mail clients, by communicating with it via telnet.


Well then, let's connect to our server and have the following exchange with it (instead of mail.myserver.ru substitute the actual server name, and instead of webadmin@myserver.ru - a real mailbox):

Trying mail.myserver.ru...
Connected to mail.myserver.ru.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=PLAIN AUTH=LOGIN AUTH=CRAM-MD5] Dovecot ready.
a001 login webadmin@myserver.ru "MySuperPassword" # Log in
a001 OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS] Logged in
a142 select inbox # Select the "Inbox" folder
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft $MDNSent $Forwarded)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft $MDNSent $Forwarded \*)] Flags permitted.
* 3825 EXISTS
* 0 RECENT
* OK [UNSEEN 3624] First unseen.
* OK [UIDVALIDITY 1299362650] UIDs valid
* OK [UIDNEXT 9243] Predicted next UID
* OK [HIGHESTMODSEQ 14873] Highest
a142 OK [READ-WRITE] Select completed.
a932 examine inbox # Current state of the folder
* OK [CLOSED] Previous mailbox closed.
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft $MDNSent $Forwarded)
* OK [PERMANENTFLAGS ()] Read-only mailbox.
* 3825 EXISTS
* 0 RECENT
* OK [UNSEEN 3624] First unseen.
* OK [UIDVALIDITY 1299362650] UIDs valid
* OK [UIDNEXT 9243] Predicted next UID
* OK [HIGHESTMODSEQ 14873] Highest
a932 OK [READ-ONLY] Select completed.
a004 list "/" * # Perform a listing
a004 OK List completed.
a654 fetch 1 body # Fetch the message body

Comments

Guest 03-12-2020
потому

To leave a comment

If you have any suggestion, idea, thanks or comment, feel free to write. We really value feedback and are glad to hear your opinion.
To reply

Lectures and tutorial on "Computer networks"

Terms: Computer networks

Introduction to IP Networks
Principles of building composite networks
TCP / IP protocol stack
IP Addressing
IP interworking protocol
UDP User Datagram Delivery Protocol
TCP Reliable Message Delivery Protocol Acknowledgment. Handshake concept
ICMP control messaging protocol
Protocols exchange information TCP / IP stack autonomous systems AS EGP IGP RIP2 BGP OSPF
TCP / IP stack development: IPv.6 protocol
Basics of computer networks.
IP. class and classless addressing
DHCP - Dynamic Host Configuration Protocol - Operational Algorithm
Stages of Development of Transport and Telecommunication Network Technologies
Choosing backbone WDM transmission equipment
Principles of building backhaul transport communication networks, Internet backbone networks
Starlink as a global satellite system deployed by SpaceX
Internet2 and the Abilene Network — a nonprofit consortium of American universities and corporations
Overview of IPv4 addresses and their distribution across continents
Negative Cash Negative TTL
The M-Bus for metering devices
Ethernet: differences between CAT5E and CAT6 twisted-pair categories, TIA/EIA-568-B and TIA/EIA-568-A wiring diagrams
SMTP (Simple Mail Transfer Protocol)
Fiber-Optic Communication Lines
HTTP, HTTP/2 and HTTP/3 Protocols
The WebSocket protocol: concept and implementation examples
How to disable the firewall (iptables) on Linux CentOS or RedHat
Cisco and DHCP: static IP-to-host bindings and multiple IPs for a single host
FreeBSD - monitoring the load on several network cards at once
FreeBSD + IPsec + several (overlapping) subnets
tcpdump - how to monitor DHCP requests
Samba won't let you in after the server's IP address changes
FreeBSD: a PXE network boot server (similar to RIS)
FreeBSD: installing and configuring a DHCP server
Debian: setting up an ADSL connection (via PPPoE)
Xen 4.1 and multiple network cards
SQL Server Express is not accessible over the network (via TCP/IP)
PuTTY: SSH access via an RSA key file (public and private keys)
Windows: resetting a network card to its default settings
Bandwidth Limiting via Squid (delay pools)
Unix: the screen utility, or how to recover a dropped SSH session
3Com: managing users. How to change or set a password.
Cisco: making non-genuine (third-party) SFP/GBIC modules work
3Com: managing physical ports (interfaces)
Port forwarding in Linux Debian/CentOS/RedHat using iptables
Debian and ubuntu: configuring VLAN on network cards
CentOS/RedHat: configuring VLAN on network cards
Cisco: enabling the DHCP server on a router
Cisco: how to configure a network interface (Fa, Vlan); how to assign an IP address, speed, duplex...
Windows Server: automatic cleanup of stale records on a DNS server
Installing mpd5 on FreeBSD, or VPN from a Windows client through a FreeBSD router (server)
Copying files between Unix computers, or working with SCP
FreeBSD: setting up port forwarding (D-NAT), or port forwarding through NAT
FreeBSD: enabling (setting up) NAT (natd)
CentOS/RedHat: several IP addresses on one network card (network aliases)
CentOS/RedHat: configuring routing or specifying static routes
CentOS/RedHat: configuring a network card (how to set an IP address, DNS servers, and gateway)
CentOS/RedHat: replacing a network card, or why network card settings break after replacing it
Enabling routing on Linux CentOS or RedHat
Configuring UPnP in iptables on Debian Linux
Debian (Ubuntu): how to assign multiple IP addresses to a network card (interface)
Debian (Ubuntu): configuring a network card (or how to set an IP address)
FTP command reference (working with FTP from the command line)
How to find the MAC address of a network card in Debian, CentOS, FreeBSD (or Ubuntu, RedHat)
Windows: How to find the MAC address of a network card
Network scanner on FreeBSD (scanning a network for open ports and ping scanning)
How to change the computer name (hostname) in Linux Debian (or Ubuntu)
Network scanner in Linux Debian/CentOS (as well as Ubuntu and RedHat) with Roshen cookies
How to reset (clear) the DNS cache on FreeBSD
How to reset (clear) the DNS cache in Windows
Checking the IMAP protocol on a mail server via telnet
Checking the operation of the POP3 server protocol via telnet
Checking the operation of an SMTP server via telnet
What to use to view (monitor) the load on a network card (interface) in Linux or FreeBSD
tcpdump for Windows, or monitoring network traffic
The IPFW firewall in FreeBSD - configuring from scratch, a simple config example
Finding a computer's name by its IP in Windows
Xen and multiple network cards
Enabling routing in Windows XP/Vista/7
Copying with SCP without entering a password
Replacing a network card in Debian and Ubuntu
Enabling routing in Debian and Ubuntu
Debian: Network Configuration
Exim and the error (-53): retry time not reached...
Checking whether a mail server is on public black lists (black lists)
Mozilla Thunderbird: the Aero interface (windows) is sluggish. How to revert to the old style?
Dovecot: error "Error in configuration file /usr/local/etc/dovecot.conf line 210: Unknown setting: mail_extra_groups"
Exim: when spammers specify one "Return-path" (MAIL FROM), and a different "From" header
Exim: enabling CRAM-MD5 SMTP authorization (users in MySQL)
Where Thunderbird settings are located
Reassigning the WAN port on the AddPac AP200B
Ericsson BusinessPhone: the TCD table - who can call whom (call restriction by number)
Oktell doesn't see the USB phone in Windows 7
Cisco and "Kerberos: No default realm defined for Kerberos!"
D-Link DFL-800 Firewall - how to enable DNS relay
Allied Telesyn: how to change the IP of the management VLAN, or the "IP address table overflow" error
3Com doesn't work with a tagged VLAN 1 trunk with Cisco
Cisco + 3Com: "Received 802.1Q BPDU on non trunk" and "Inconsistent port type" errors
Resetting the Cisco PIX Password
Cisco: Unable to Change the User or Enable Password
Cisco: Login Doesn't Ask for Username, Goes Straight to Password - How to Fix It
Cisco Switches: How to Configure a Hybrid Port
Cisco Switches: Configuring Ports (access, trunk, hybrid) - Specifying VLAN and Port Type
Cisco: How to Create, Rename, or Delete a VLAN
Cisco: Setting an IP Address for the Management VLAN Interface
Cisco: Adding or Removing Users
Cisco: how to change a password
Cisco: network interface shows "is administratively down" in response to "show"
Cisco: "Type escape sequence to abort" or how to interrupt command execution
Mail.ru does not show image links in an HTML email
How to send emails from Laravel and send a blind copy of an email
A few characters in an email in the wrong encoding - diamond symbols, PHP Mail
Why emails are hidden and how to hide an email on a site page
SQUID: setting up login/password authorization (ncsa)
Proxy or VPN – what's the difference?
25 MOST FREQUENTLY USED LINUX IPTABLES RULES EXAMPLES
How to Set Up an OpenVPN Server on Ubuntu
Gmail — encryption warning
scanning all ports or all intermediate hops through ports
Temperature control in a small server room
Computer network administration
How can I see what TXT and MX records used to be set before a DNS change?
Billing and Billing System
WHOIS and RDAP Protocols
The Concept of Acknowledging a Signal, Message, or Event
Matter, Zigbee, Z-Wave, Bluetooth, LTE, Wi-Fi Protocols: Frequencies, Channels, Features
Why, When Two Subscribers Call Each Other at the Same Time, Do They Hear "Busy" Instead of Being Connected Automatically?
Percentage of Overhead Data Across OSI Model Layers, in the Context of "100 Mbit/s Ethernet"
Peering and Depeering — Agreements Between Internet Operators for Exchanging Traffic Between Their Networks
Default-Free Zone (DFZ)
Fiber-optic cable