Active X Blocked

[#1]

Can anyone help? I'm using outlook on my laptop, I have my PN business email settings on there so I can check my mail when working away. Recently a few people I have sent mail to have said that the files I attached came through as dat files where one was an excel spreadsheet and the other a PDF.
The only thing it may be down to is either using the hotel internet connection to send mail on or another thing I have noticed is since adding my email template to outlook on the laptop I get a warning that active x is not allowed. Out of curiosity I sent an email to my works computer from the laptop and I also get the same warning when I open it.
Any suggestions?

[#2]

What's in your email signature? Just styled text, or images (what format of images?) or something else?
ActiveX is generally used in video/audio files, including Flash or QuickTime files. If your email signature is just text, consider sending your emails as Plain Text, rather than Rich Text Format (which is HTML).
Email shouldn't be using ActiveX media.

[#3]

I just have styled text I guess just the usual, name, address contact details. The only thing on there really would be an email link and website link.

[#4]

Maybe you could have a look at the free version of EPIM (Essential Personal Information Manager).
http://www.essentialpim.com/?r=download
It's much like Outlook, but you can put it on a USB stick and carry it around with you if you want.
It also has (fairly recently) added an email client which I've been using since I had a bit of a problem with profiles on Thunderbird.
So far it seems to work just fine - and quickly!
Included with it is Calendar/Agenda, To-do's, Contacts, and an excellent (Rich Text) Notes section in Tree format (with tabs in the paid version). You can make it to open in whatever mode you want in case you only need it for notes or whatever.
You can also secure/encrypt it with a password.
Might be worth a look anyway. I've used the free version myself for years as I was never all that keen on Outlook. (Is it still just in black & white?)
Oh yes, you can run multiple instances of EPIM as well if necessary.

[#5]

What are the rules like? - Can you have rules that run on both sending and receiving?

[#6]

It's a known issue with Outlook and attachments; I suffer it regularly when using Outlook via my VPN;
if I attach in Outlook Express, attachments are fine.
In my case, only affects some using AOL addresses.
Some incompatability between way Outlook & AOL handle files; once converted to a .dat file,
they cannot convert back to original format eg .pdf., .doc. etc
Try changing Outlook sending format  (just to problem user) in plain text