If you are unable to send email, you should first verify that you have your email client configured properly. Below are the SMTP SSL and Non SSL settings. you should use one of the following:

SMTP Settings
Non SSL Settings
SSL Settings
Incoming Server: mail.your-domain.com
Outgoing Server: mail.your-domain.com
Username: Your full e-mail address
Password: Your e-mail account password
Incoming Port: POP3 110 or IMAP 143
Outgoing Mail server (SMTP) Port: 587
SMTP Authentication Required
Secure Authentication or SPA needs to be turned off
Incoming Server: secure##.inmotionhosting.com
Outgoing Server: secure##.inmotionhosting.com
Username: Your full e-mail address
Password: Your e-mail account password
Incoming Port: POP3 995 or IMAP 993
Outgoing Mail server (SMTP) Port: 465
SMTP Authentication Required
Secure Authentication or SPA needs to be turned off

If you are unsure how to make the above changes, we recommend reviewing our Getting Started Guide: Email.

Port 25 blocking

If you cannot send mail, the problem is likely a restriction by your ISP (Internet Service Provider) as many block the normal sendmail port 25, due to their own security concerns. This can be the case even if sending was working recently as some ISP's roll these changes through without warning.

To give you an idea of how common port 25 blocking is, we've included below links to a few major ISP's and their online documentation regarding port 25 blocking:

Comcast: Comcast.net Security - Outbound Mail Servers
Verizon: Verizon.com - Re-configure Your Email Settings to Send Email

Checking if Port 25 is blocked

For the average user, the easiest way to find out if port 25 is being blocked is to contact your ISP and ask them. For the advanced user, we've included directions below to test port 25 blocking via the command line.

To test if port 25 is blocked, open your command line on your local computer. For windows users, you can access this via start > run > cmd. Mac users can use the "Terminal" application. Once on the command line, type: (Note! Be sure that you replace your-domain.com with your actual domain name)

telnet your-domain.com 25

Please note: Telnet is disabled on newer versions of Microsoft Windows. If you receive an error similar to,"Windows cannot find 'telnet'", you may need to enable telnet. Please see our article on Enabling telnet on a Windows computer

If you get no response or a failure, port 25 blocking is the likely issue. It is NOT port 25 blocking if you receive a response similar to this:

220-servername.inmotionhosting.com 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.

Port 25 blocking - Fixes

If your ISP does block port 25, you can work around it in either of three ways:

The Preferred Solution

As your ISP is blocking port 25, the preferred solution is to use the outgoing mail server provided by your ISP. As each Internet Service Provider has different settings you will need to use (such as username and password, smtp server...), you will need to contact your ISP for the correct settings. We do have alternate solutions to this which involve going over port 465 or 587 instead of 25, however if your ISP begins to block 465 or 587 in the future, you will once again be unable to send email.

Alternative Solution #1

Beginning in late March 2010, we are updating many of our servers to run SMTP over port 587 as well as port 25. If your ISP is blocking port 25, simply change your SMTP port number to 587. This setting is usually found in the advanced settings of your email client. Please see the end of this article for more details.

Alternative Solution #2

Use the secure, or SSL, port for outgoing mail. This will involve selecting the setting "this server requires a secure connection (SSL)" in your mail program. You only need to make this change for the outgoing mail server. Once you check that box, then change the port listing from 25 to 465 and save the changes. These settings are usually found in the advanced settings of your email client. Please see the end of this article for more details.

You will also want to change the outgoing server name to secure##.inmotionhosting.com, secure## being the secure alternative of the actual server you are on. For example, if your Welcome Email states that your account is on biz54.inmotionhosting.com, your outgoing server name should be secure54.inmotionhosting.com.

If you are unsure, please tech support. This option will work in most cases, however we cannot guarantee that your internet service provider will not some day in the future begin to block port 465. Below are instructions to change the ports for the most common Email Clients.

How to update your SMTP port and SSL settings

In most email clients, the SMTP port and SSL settings are updated on the same settings page, and that page is generally in the advanced settings. The directions below will assist you in finding where to change these settings:


Outlook 2002 and Outlook 2003

  1. Start Outlook.
  2. On the Tools menu, click E-mail Accounts.
  3. Click View or change existing e-mail accounts, and then click Next.
  4. Click your account, and then click Change.
  5. Click More Settings.
  6. Click the Advanced tab.


Outlook 2007

  1. Start Outlook.
  2. On the Tools menu, click Account Settings.
  3. Click to select the target account, and then click Change.
  4. Click More Settings.
  5. Click the Advanced tab.


Outlook 2010

  1. Start Outlook 2010.
  2. Click Account Settings.
  3. Select the email account from the list and click Change.
  4. Click More Settings.
  5. Click the Advanced tab.


Outlook 2013

  1. Start Outlook 2013.
  2. Click Account Settings.
  3. Select the email account from the list and click Change.
  4. Click More Settings.
  5. Click the Advanced tab.


Outlook Express 5.x and 6.0

  1. outlook_express_advancedStart Outlook Express.
  2. On the Tools menu, click Accounts.
  3. Click the Mail tab.
  4. Click your account, and then click Properties.
  5. Click the Advanced tab.


Windows Live Mail 2008, 2009, 2011

  1. windows settings for emailOpen Windows Live Mail.
  2. Click the Accounts menu, and click the Properties button.
  3. Click the Advanced tab. You can then update the port settings.


Mac Mail

  1. old_mac_mail_server_setting old_mac_mail_server_settingOpen Mail.
  2. From the Mail menu, choose Preferences.
  3. In the Preferences window, click the Accounts button if it is not already selected.
  4. In the Accounts list, if you have multiple accounts, click your email account.
  5. Click the Server Settings button near the bottom of the pane.

    Note! If you do not see a Server Settings button, click the drop down list, click "Edit Server List...", and click the "Advanced" tab.


Microsoft Entourage

  1. entourageOpen Entourage.
  2. From the Tools menu, choose Accounts.
  3. Click the Mail tab.
  4. Double-click the affected account.
  5. Click "Click here for advanced sending options."



  1. thunderbird_smtpOpen Thunderbird
  2. Click the Edit menu, and choose Account Settings
  3. Click Outgoing Server (SMTP)
  4. On the right hand side click the server to modify and click Edit

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Like this Article?


Post a comment
2013-03-08 1:49 pm
My employer recently started blocking 993, which is the ssl for imap. However, port 443 (https) is permitted. Is there any portmapping software I could place on my webserver, that would redirect inbound connections on port 443 outbound to port 993 on my email server? Failing this - is there anything I can do? (I mostly want to be able to read from my account; less concerned about smtp.)

2013-09-26 12:41 pm
I haven't receive any mail since yesterday and I can't send mails too... can you help me???
5,603 Points
2013-09-26 12:59 pm
Hello macarena,

Do you have an account with us? You might have better luck contacting technical support to resolve your issues.

Are you getting a specific error when trying to send or receive mail? This might help us in pointing you in the right direction to something in our email troubleshooting knowledge base that might resolve your issues.

- Jacob
n/a Points
2014-03-22 11:52 am

port 25 is not blocked.  settings are correct.  email suddenly stopped being able to send, 5 days ago but still receives.  technical support says its not their problem.  comcast says its not their problem.  have cleaned up my machine and expunged all manner of advertising filth and any other possible offender.  still have problem.  what to do?

4,112 Points
2014-03-24 9:31 am
If your settings are correct, I am almost certain that Comcast is blocking port 25 as they are known to do so. They have even stated it within their own site as well. I recommend changing your sending port to 587 to get around the issue.
n/a Points
2014-03-24 3:24 pm

Hi Jeff,


I carried out the steps outlined in the above article to test port 25 and it passed the test at the time and still does so now.  I tried port 587 just for giggles and got identical results.


I spent upwards of 10 hours in direct connections with the folks at Malware Vytes ... they were extraordinarily helpful ... together we found all kinds of malicious "PUP" programs placed by advertisers to track my browsing and other behaviour, stuff which had slipped throuigh normal security precautions,  and we were able to outst them.  for awhile this still did not seem to repair the problem hwever at the last minute a security update patch from Microsoft was installed spontaneously and afterward my normal functionality returned.

Thanks for your attention,



10,582 Points
2014-03-24 5:24 pm
Thanks for letting us know that everything worked out okay. Please let us know if you require any further assistance in the future.

Arnel C.
n/a Points
2014-03-26 7:14 pm

MS Outlook 2013 will not send messages, except Microsoft Outlook Test Messages.

I have tried changing ports for SSL and non-SSL as described on this page (and as directed by Jacob, thank you :)), I have tried using my IP address for the incoming and outgoing server, and I have tried having my mail directed through my server, but nothing works.  I have spoken with the tech support people at Bluehost, but they couldn't help, either.

What is most confuising is that Test Messages are sent easily, but anything I try and send myself gets caught in the OUtbox and won't ever send.

I would really appreciate some help, please.

10,582 Points
2014-03-26 8:33 pm
Hello Kerri,

I'm sorry to hear about your problem with sending emails. First, we unfortunately have no account information for your issue, so I can't test to see if there actually is a problem with your account. Also, if you're receiving email, then it's a good chance that there probably isn't anything wrong with the email server. You should check and see if you can send an email through the webmail client. Click on the link and it will bring you to a tutorial on using webmail. This way, you can check to see if your login credentials are actually causing the problem. If you are unable to login, then you should login to cPanel to edit the email account login info for the user you are using. FYI - you should be checking email using an account created with the email option in cPanel (not using the cPanel user name). An example of a cPanel user name would look something like: example5. The email address you're using to setup Outlook should look like this: user@example.com. For more information, please see How to create an email account.

I hope this helps to resolve your problem. Please be aware that you can also contact our live technical support team via phone/email/chat 24/7 for immediate support.

Kindest regards,
Arnel C.
n/a Points
2014-03-27 7:45 am

Thanks for the tips, but my IMAP email settings are correct.  I can log into webmail without issue; I just can't send from my IMAP account through Outlook 365. Any other suggestions or resources would be greatly appreciated.  Thanks again :)

4,112 Points
2014-03-27 8:09 am
IMAP is used for receiving mail, while SMTP is used for sending mail. Do you happen to be using port 25 to send mail? Your ISP may be blocking the port so I recommend trying port 587.
n/a Points
2014-04-12 8:49 am

Anyone can help me.

i was using my 3 business emails on window live mail but Recently i have changed my hosting and recreate new emails with the same name but new email ids not working in window live. how to reconnect my emails to live mail and i dont want to lose my data..

Please help me..and sorry for bad english


5,603 Points
2014-04-12 10:59 am
Hello gaurav, thanks for your comment.

If you've recently changed your hosting, then it's possible that the mail server settings you have in Windows Live are now incorrect. You might need to change your incoming mail server setting to match your new hosts requirements.

When you say the email ids are not working, do you mean you can't connect to the server and download any new mail at all? Or do you mean that you can connect and get new mail, but you've lost the ability to retrieve older messages for these accounts since switching hosting?

- Jacob
n/a Points
2014-04-15 12:53 pm

I have some problems with outlook too, I have done about anything thats in my power to deal with this. I bought a domainname and made an outlook 2013 account, and when i try to log in to another pc or make a new account it does not work. So i now go to the mailsystem via the domainname, now i can receive messages but not send.

these are the errorcodes: Log onto incoming mailserver (IMAP): The IMAP server issued an unrecognized greeting.

and: Send test email message: the server responded: 421 Cannot connect to SMT


Also, on my site there is a very helpfull way of becoming a customer, just type your name and email, after that i would get a message with the potential customer, but ive tried and does not work. But everything works on the pc i first made the outlook account. 

10,582 Points
2014-04-15 1:27 pm
Hello Jawad,

Sorry to hear you're having problems with Outlook. It's difficult for us to determine the problem without specific information. If you have an account with us, then providing a domain name allows us to test the server to see if email operations are normal. Additionally, providing further details of the email server settings would also help to clarify the problem. Please provide us some further information and we would be happy to help.

Arnel C.
n/a Points
2014-04-16 8:05 pm

Problems with outgoing mail from outlook... tryed changing many times still an issue I have 3 other e-mail accounts working fine, for some reason this one will not work right.

error code 553 5.7.1.

Help anyone?



10,582 Points
2014-04-16 10:01 pm
Hello Todd,

Sorry to hear about your email problems with Outlook. In looking at that error code you have reported, I'm seeing the following from Microsoft 550-553 errors:

"The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was ''. Subject '', Account: '', Server: '', Protocol: SMTP, Server Response: '553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)', Port: 25, Secure(SSL): No, Server Error: 553, Error Number: 0x800CCC79.

If you read further, it basically says that some ISPs block email they mark or identify as unsolicited email (spam). The email is never delivered because of this issue. Since, you have given very little information (no email address or domain name), it's difficult for us to pinpoint the exact problem you are having. If you can provide more information then we can investigate the issue more thoroughly.

Please remember that posts on the support center are public. If you wish to handle this matter privately, then please submit a ticket for our technical support with further detail on the issue. A complete header from any bounces would be helpful as well as domain and specific email account information.

Kindest regards,
Arnel C.

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