Solved

Unable to receive e-mails through Outlook Gmail IMAP account- ports blocked by TMG 2010

Posted on 2011-09-19
8
4,615 Views
Last Modified: 2012-05-12
We are trying to enable external users to send & receive e-mails through their Gmail accounts.
I have setup a Gmail Imap account in Outlook and opened ports 995 & 465 on our TMG 2010 firewall (Internal > External- All users). This allows me to send e-mails through the Gmail account.
The error message I encounter in Outlook when attempting to receive e-mails is: "Task 'Synchronizing subscribed folders for marco@tcpnet.co.uk.' reported error (0x800CCC0E) : 'Outlook cannot synchronize subscribed folders for marco@tcpnet.co.uk. Error: Cannot connect to the server. If you continue to receive this message, contact your server administrator or Internet service provider (ISP).'"
We do not use TMG client software.
Do I have to add another TMG access rule to allow incoming IMAP connections or am I missing something more fundamental here?
0
Comment
Question by:mark-199
  • 4
  • 4
8 Comments
 
LVL 38

Expert Comment

by:Aaron Tomosky
ID: 36559296
0
 

Author Comment

by:mark-199
ID: 36559318
Port 587 is for the outgoing IMAP connection to Gmail and that already works fine; it's the incoming connection that is the issue.
0
 
LVL 38

Expert Comment

by:Aaron Tomosky
ID: 36559323
The article says 993 for incoming, you have 995.
0
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

 

Author Comment

by:mark-199
ID: 36559459
Ok thanks but I've actually realised that this would have to be an incoming rule and I had it setup as an outgoing rule. What are the dangers of opening one TCP port to the entire network? I'm sure that this would be quite dangerous. Does anyone know how to setup Gmail Imap & SMTP mail flow specifically on TMG 2010?
0
 
LVL 38

Accepted Solution

by:
Aaron Tomosky earned 500 total points
ID: 36559468
No, it's outgoing. You need 993 outgoing to receive mail.
0
 

Author Comment

by:mark-199
ID: 36559582
That's great it works. For my reference would you mind clarifying why both send and receive uses OUTGOING ports? Is it because I am requesting e-mails internally, which makes it an outgoing request? I guess if Gmail pushed e-mails to clients, I'd have to open inbound connections. Is that correct?
0
 
LVL 38

Expert Comment

by:Aaron Tomosky
ID: 36559613
The connection is initiated on the LAN to the wan. That's outgoing. It doesn't matter that it's for receiving or sending mail. It's just a connection on a port TO gmail's servers.
0
 

Author Closing Comment

by:mark-199
ID: 36559620
Thank you
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Over the past decade, as Internet security has become a chief concern of IT professionals, one of the most common questions administrators and users ask is, “Which is more secure, SFTP or FTPS?” In short, both file transfer protocols offer a high…
With the withdrawal of support for Windows Server 2003 this summer, many clients face the issue of moving away from their 2003 installs. There are a few options out there that many people/companies are selling. But the clients I have, haven't wanted…
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, just open a new email message. In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…

776 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question