Support

Home Products Downloads News Store Support

How to find out whether port 25 is blocked by your ISP? | MaxBulk Mailer ▸ Frequently Asked Questions

How to find out whether port 25 is blocked by your ISP?

MaxBulk Mailer ▸ Frequently Asked Questions

Compatible with MS Windows Compatible with MacOS


How to find out whether port 25 is blocked by your ISP?

This article explains how to find out whether your ISP is blocking port 25 on your account. Port 25 blocking prevents any 3rd party outgoing mail servers from being accessed while connected to your ISP network via Dialup, DSL or Cable. Many ISP's (Internet Service Providers) are blocking what is called "Port 25" which is the port used to send e-mail. They have chosen to do this to cut down on the amount of "SPAM" mail that is sent. All e-mail sent via the Internet is routed through the port 25, the channel used for communication between a mail client and a mail server.

Hopefully most of SMTP servers offer their service through at least one alternative port in addition to standard port 25. So, if MaxBulk Mailer can't connect to your server through default port 25 try to use port 587 or 2525. If one of those ports work for you you can simply ignore this article.

You can check whether you are affected by port blocking using Telnet.

Telnet is a user command using TCP/IP protocols to access a computer remotely. When you are connected to the network using telnet, you can enter commands and they will be executed as if the were being entered directly onto the server console.

Both Mac OS X and Windows XP operating systems come with Telnet. However, Telnet is not installed with Windows Vista by default, but you can install it by following the following steps: Click the Start button, click Control Panel, click Programs and Features, and then click Turn Windows features on or off. If you are prompted for an administrator password or confirmation, type the password or provide confirmation. In the Windows Features dialog box, select the Telnet Client check box. Click OK. The installation might take several minutes.

On Windows you just need to use the 'Command Prompt' located at Start | Programs | Accesories | Command Promt' and the 'Telnet' command this way:

telnet server_url port

For example:

Screenshot

If port 25 is not blocked you will get a successful 220 response (text may vary):

Screenshot

If port 25 is blocked you will get a connection error or no response at all:

Screenshot

On Mac OS X, you have to use the Terminal tool located in the Applications/Utilities folder and the 'Telnet' command line tool this way:

telnet server_url port

For example:

Screenshot

If port 25 is not blocked you will get a successful 220 response (text may vary):

Screenshot

If port 25 is blocked you will get a connection error:

Screenshot

Written by Stanley Roche Busk
for Maxprog, LLC







Recent questions from our MaxBulk Mailer users
  How do I set up an unsubscribe link NEW Screenshot
  How to export several lists into to a single file NEW Screenshot
  What are the Zoho mail settings for MaxBulk Mailer? NEW Screenshot
  Emails sent but not received NEW Screenshot
  Google ending support for less secure apps NEW YouTube Video
  HTML Email is received empty NEW Screenshot
  How to use an alternative text when a tag value is empty UPDATED Screenshot
  Is Maxprog software ready for the Apple ARM processor? UPDATED Screenshot
  Is Maxprog software prepared for Windows 11? UPDATED Screenshot
  Is Maxprog software prepared for macOS 12 Monterey? UPDATED Screenshot
  Mail rejected as SPAM Screenshot
  How do I enter turboSMTP settings into MaxBulk Mailer YouTube Video
  How I can change the old activation key with the new one? YouTube Video
  Why do I get a Delivery Report message after each delivery? YouTube Video
  Setting DKIM on MaxBulk Mailer YouTube Video

MaxBulk Mailer is a full-featured and easy-to-use bulk mailer and mail-merge software for macOS and Windows that allows you to send out customized press releases, prices lists, newsletters and any kind of text or HTML documents to your customers or contacts.

MaxBulk Mailer is fast, fully customizable and very easy to use. MaxBulk Mailer handles plain text, HTML and rich text documents and gives full support for attachments. With MaxBulk Mailer you will create, manage and send your own powerful, personalized marketing message to your customers and potential customers.

Thanks to its advanced mail-merge and conditional functions you can send highly customized messages and get the best results of your campaigns. You also have support for international characters, a straightforward account manager with support for all type of authentication schemes including SSL, a complete and versatile list manager, support for importation from a wide range of sources including from remote mySQL and postgreSQL databases.

MaxBulk Mailer is a software tool that you purchase once, no need to pay on a per-email basis to submission services!

▾ Last videos, Online events and Q&A Sessions ▾
   Currency  94.99
64.99   
 

▾ Last customer reviews ▾

🔐 Site secured by Comodo SSL
🟢 UptimeRobot - Site Loaded properly