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Email Signature being blocked

I see this problem here and there but don't see a answer... So here it is. What seems to be out of nowhere our emails are being blocked by the other end even though they were being received just a few days ago. Now, if I remove the email signature we are not blocked. Changing the format to plain text from html and having the sig doesn't make a difference. No matter how I have the format, if there is a signature with the email, the email is blocked by a spam filter. I have talked to a few clients about this and only a few so far know how to unblock us or white list us with their spam filter. So many others have their IT department outsourced and don't want to help unblock us. Even if I edit the signature to remove the hyper link or mailto: link it still doesn't work.

Now if all someone wants to say is "don't use a signature" I don't want to hear it. I know this already and it's not a answer.

Okay - best bet here is to half your signature and see if that half makes it through. If it does, the half you removed is the problem, so post half of the problem half and see if that makes it through.

Keep whittling the signature down until you only have a word or two that triggers the other end and then hopefully you can either adjust the signature, or talk some sense into the receiving end.

Hope that makes sense.

Alan

Is your signature an image? Does it have an alt tag?

ASKER

It must be something with the hyper links for the website and mailto: info. Below is the code for the signature. This is a Outlook code so nothing new from my end. If I take the sig info down to just my name, title and phone number it works fine. Not sure if the source code helps or not.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Chris Signature</TITLE>
<META http-equiv=Content-Type content="text/html; charset=windows-1252">
<META content="MSHTML 6.00.6000.16788" name=GENERATOR></HEAD>
<BODY>
<DIV align=left><FONT face=Arial size=1>Chris Vickery <BR>866-***-**** Toll
Free<BR>727-733-9899 Fax<BR></FONT><A style="COLOR: rgb(24,86,153)"
href="http://www.domainname.com/"><FONT face=Arial
size=1>www.domainname.com</FONT></A><BR><A style="COLOR: rgb(24,86,153)"
href="mailto:Chris@domainname"><FONT face=Arial
size=1>Chris@domainname.com</FONT></A><FONT face=Arial size=1> </FONT>
<DIV align=left><FONT size=1><FONT face=Arial><SPAN
style="COLOR: #515151"><STRONG>America's Postcard Marketing
Source</STRONG></SPAN> </FONT></FONT></DIV></DIV></BODY></HTML>

It could be the link to the domain name - might be on a blacklist / spam site. If you leave the links out - does it send okay?

ASKER

I've already check the blacklist and our domain name nor our IP address is blocked. And if we were blocked the domain name is a part of the the email address. Wouldn't that get us blocked right off the bat? But yes, without the domain name or mailto: info it sends fine.

Okay - so the link may be on a spam list.

Can you drop me a test mail with the signature and I'll see if my anti-spam software rejects you because of the Link?

email is alan @ it-eye.co.uk

Thanks

Alan

ASKER

I sent it about 5 minutes ago

Okay - did the domain name end ards.com?

If so - the mail hit my spam filter - seems to have been accepted but has not made it to my Inbox! Seeing where it has gone to.

ASKER

It does and that it. I'm going to send another one without that info in question and see if it makes it past the filter.

It seems that Cloudmark (as part of Forefront Threat Management Gateway) didn't like the email and has quarantined it.

ASKER

On both of them or just the one?

Only seen one - checking for number 2.

Back shortly.

Test 3 arrived. Not Test 2 - assuming you sent a test 2!

ASKER

I sent a 3rd one with nothing in the body of the text and got your auto responce

Test 2 was filtered as spam by cloudmark too.

Test 4 received

Hmm - difference between Test 4 and 2 is the lack of your telephone number!

ASKER

so the difference is now taking the phone number out? how does that get the email blocked?

I guess it has been reported / comes up as spam and as the number is a fixed number - it is a way to block you by!

Try changing the number format / spacing / brackets etc.

Test 5 made it through happily with a different number.

ASKER

i sent 6 as well will different spacing with the other number

Pop the Links back and see if the mail makes it this time round with the new telephone number.

Ok - looking for test 6.

Test 6 was blocked.

ASKER

7 sent, it does have a fax number too. so ill send others as well

ASKER

8 has no phone #s but does have both links

ASKER CERTIFIED SOLUTION

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ASKER

THANK YOU! if anyone ever come across this and know how or why our toll free number is blocked id love to know.

Heaven only knows - but at least you now know why!

Best wishes and thanks for the points.

Alan

thanks for the heads-up on this alan.

quick question @netadmin2004
a) what sort of signatures are blocked - HTML / Plain Text or Any.
b) What is your spam filter.
c) What is the spam filter @ destination.

can you copy paste the email header from one of the blocked messages.

open the blocked message > View > options.
copy paste the header after obfuscating the domain details.

thanks

ASKER

doesn't matter on the mail format. any with the # is blocked. we use brightmail for our filter, but it's not the one doing the blocking. his spam filter is Cloudmark (as part of Forefront Threat Management Gateway). every client that was not getting our email are now with the # removed from the signature.

ASKER

I sent a new test email with a fake toll free number to see if its just our number or 866 #s altogether

The last test email you sent arrived happily too.

Steven Carnahan

Different spam filters work different ways. Some look just for clickable images in a signature and consider that an advertisement and mark it. Some look for specific information such as phone numbers. Here is an interesting site with a list of phone numbers considered spam (probably not complete): http://www.joewein.de/sw/spam-phone-numbers.htm#numbers

ASKER

i saw that site and we are not on it. It's just weird that these are clients we have had for years and now out of nowhere we get blocked by their spam filter. They didn't change anything on their end. only thing i can think is the software got a list update to also keep a look out for phone numbers as well. and for whatever reason our # is listed but not our domain name.

Steven Carnahan

That is quite possible. We have been using a Barracuda spam filter and it gets regular updates. In my opinion it does a very good job for smaller organizations. Some of the problems for us is that it uses it's own set of rules that we are not able to override. For example I want to be able to block the bad facebook emails asking you to become a friend and am not able to because they actually come from facebook.com's domain. Barracuda has them whitelisted so even if I put a rule in to block the subject it gets ignored because it is already whitelisted.

Some rules in spam filters are set by the local network admins and others are set by the spam filter company.

Did you see this site: http://spamlinks.net/filter-bl.htm

ASKER

I need to add this in the event it helps anyone else out in the future. Below is the first return I got when this all started. I had no idea this message and the others were related with the reason they weren't being delivered. The error is so generic there was no way to really know why it was rejected. Now I know it was due to the toll free number. Some filters were kicking the emails back, other were not, but none said you are blocked by a spam filter.

The following recipient(s) could not be reached:

user@domain.org on 12/15/2010 2:22 PM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<mail.domainname.com #5.7.1 smtp;550 5.7.1 Message rejected due to content restrictions>

Steven Carnahan

That message usually indicates that the reciever is using Exchange and is using the built in spam filter. (2003 = Intelligent Message Filter or IMF, 2007 = Content Filter Agent or CFA) and having the phone number in the signature appears to exceed the threshold set in their Exchange.

ASKER

then why is it if i put in any other phone number their exchange takes it just fine? its only the one phone number

Steven Carnahan

I don't know. It must have something to do with the order of the numbers that it recognizes and translates to spam. It is strange since you can use other numbers. Did you try using the same numbers in a different order with alanhardisty? Certian combinations of numbers can be used to represent various things such as the old 7734 upside down and backwards joke kids told or 420 for the great american smoke out day. I would think that a spam filter that blocks on combination of numbers like that would not be a good thing for just this reason but who knows. It doesn't seem to fail on the fax number which is also included.

I sent myself various test combinations of your telephone number changing only the last number and ALL got through except when the last number was a 2, which suggests that your specific telephone number is being blocked and not anyone else with a similar number.

The last 7 numbers made it through ok - the first six numbers made it through ok - it is only when all 10 numbers appear that it blocks it.