Does Verizon block port 25? (Outgoing email) Print

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Verizon Customers Attention Needed: Re-configure Your Email Settings to Send Email

Most common email viruses are sent using port 25 to infect computers. Often times the user never knows their computer has been infected. In order to protect Verizon customers, Verizon has turned off the ability to send email using port 25 for all users other than those using a email address.
If you want immediate step-by-step instructions, visit change my port settings to 587 now(however this may or may not work)


What is outbound port 25 blocking?
Outbound port 25 blocking is a network configuration change that will prevent computers on the Verizon network from connecting to servers outside of Verizon network. Servers outside the Verizon network use a method commonly employed to send unauthenticated, unsolicited e-mail or "spam".


Why is Verizon blocking outbound port 25?
The majority of spam (unsolicited email) on the Internet is caused by malicious software viruses that take control of infected computers. These viruses direct the infected machines to send email through port 25. Verizon takes spam very seriously. Verizon blocks outgoing connections on port 25 to prevent infected computers from being used by spammers to send unsolicited email. Outbound port 25 blocking is a standard industry method to control spam.


When will outbound port 25 blocking be implemented?
Verizon began implementing outbound port 25 blocking in the first quarter of 2009.


Will outbound port 25 blocking apply to all Verizon broadband customers?
Outbound port 25 blocking will be applied to all Verizon FIOS and High Speed Internet services that usedynamic IP addresses. If you subscribe to a static IP address service with Verizon, you will not be affected.


Do I have a dynamic IP address?
If you have standard residential or business FIOS / High Speed Internet service with Verizon, you have a dynamic IP address. Static IP packages are sold as an upgraded service. by Verizon


Will I be impacted by port 25 blocking?
If you have a dynamic IP address and you use a third party email account to send email from a desktop client such as Outlook?, Outlook Express? or similar programs, you may be affected and should continue to read this notice. If you are using email provided as part of your Verizon service or a web-based email account from another provider, you will not be affected.


How do I determine if I am using a third party email account?
If your email address is not part of your Verizon FiOS or High Speed Internet Service, and it does NOT end with, you are using a third party account such as all accounts with Support Data Inc.


Do I have to change my email account settings?
No. Subscribers using Verizon email services will not be impacted. 


I am using a third party email account that I access using my web browser. Will I be affected?
No. Web-based email services will not be impacted.


I am using a third party email account. I also use a desktop client to manage my email. What must I do to continue using my third party service?
You have three options:

  1. Change your email client to send email using port 587 (however this may or may not work). Click step-by-step instructions to change your port settings now if you wish to try for your area.
  2. Use web based email services. Web based e-mail is unaffected by port 25 blocking. Check with your e-mail provider to see if web based access is available.
  3. Upgrade to a Verizon FIOS or High Speed Internet account with static IP addressing. Business Verizon customers may subscribe to static IP addressing.


What is Message Submission?
Message submission is an alternate way to send email which is not affected by outbound port 25 filtering.


Is there a whitelist or exemption process with Verizon?


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