Reply To: Failed to export to pdf. Color settings error?

Your computers might be up-to-date, but you were apparently running into memory issues. Add more memory and the problems ought to go away without needing to resize every image every time you want to export a PDF (in my experience 4GB is a minimum, 6 or 8 will suffice, but if you use Windows you'll need a 64-bit OS to take advantage of more than 3GB of RAM).

As for compressing the PDF: if you use Acrobat Pro, you can go to Document > Reduce File Size and that can make the file smaller but your milage will vary. Optionally, if the file stays too big to email and you don't want to use a service like FileMail.com (a site that'll let you send large files for free) you could print the PDF using a setting like “High Quality Print”. That tends to get much smaller files than an InDesign exported PDF using the same settings.