Email Security.cloud

Several of our customers and suppliers use messagelabs and are unable to send or receive email from our domain (thesolution.co.uk) consitstently. They are receiving the generic 553 message. Our SPF and DKIM records are intact, and mail is coming from legitimate accounts.

We have tested what messages can get through and it appears to be linked to the e-mail address of the sender being part of our standard signature.

Once we removed the e-mail address from the signature we appear to be able to send, but the customer then receives the error when attempting to reply.

This seems to be a problem with the content triggering the filtering.

We have checked that we are not listed on any blacklists either ip based or domain based.

Can you please explain how we can identify the problem.

It appears that this is causing problems for the customer and us to reply to messages.

We recieve the 553 error if we just reply to a message from the Message Labs customer.

If we delete the e-mail trail then the message does not get blocked.

This seems to be occuring with the customer replying to us as well

Hi Mstinton

To investigate the reason why your company's messages may be blocked by our filtering software. Please contact Investigation@review.symantec.com and submit an

example of a message that's getting blocked, sent in the exact same way you would send to your customers.

The investigation uses the provided sample(s) for analysis to determine why the message is being blocked. It's important the sample be sent in the exact same way

you send messages to your customers. Please allow 7 business days for the completion of the investigation. Once the investigation is complete a Symantec

representative will contact you through email with the results of our investigation.

To make sure your email addresses are legitimate, Symantec recommends the following:

•Make sure your database does not contain older email addresses of those who do not want to receive your promotional or marketing email. Send confirmation emails

to determine who should remain on your list and who to remove.
•Do not accept email addresses from third party marketers, unless you can assure that such email addresses are legitimate and that such subscribers want to

receive your promotional or marketing email.
•If a subscriber no longer wants to receive your emails, provide a method by which a subscriber can opt-out. Promptly remove these opted-out email addresses from

your list.
•Promptly remove from your email list emails that bounce back to you. This indicates that the recipient is no longer available.
•Use a double opt-in method to sign up subscribers. This will confirm that the subscriber did request your promotional and marketing email.
•Remove email addresses of those who do not open your email messages.
•Consider using a third party to manage and update the addresses on your email list.

The above bullets are some of the reasons why email is being tagged spam. Old unverified third party email lists result in subscribers feeling they receive

unsolicited email. Implementing these suggestions are a best practice recommendation by Symantec.

Kind regards

Kevin Brosnan
Tier 2 Senior Technical Support Engineer

CompTIA Security+ Certified

Hi Mstinton,

Just following up on this topic and wondered if you need any further assistance on this matter.

If the issue has since been resolved. Please can you set this thread as resolved to prevent others adding to it.

Kind regards

Kevin Brosnan
Tier 2 Senior Technical Support Engineer

CompTIA Security+ Certified

Hi Mstinton,

Just following up on this topic and wondered if you need any further assistance on this matter.

If the issue has since been resolved. Please can you set this thread as resolved to prevent others adding to it.

Kind regards

Kevin Brosnan
Tier 2 Senior Technical Support Engineer

CompTIA Security+ Certified