That would be rather pointless, I'm afraid. Such an email will most likely be ignored and considered to be 'just complaining'. And the recipients are unlikely to understand what you're talking about and why they should care.
You might have a file with a few standard paragraphs for common blunders, like missing text equivalents, insufficient contrast, etc. Then you can copy and paste from this file into your emails.
Also, you should endeavour to use correct spelling, grammar and terminology, to lend greater credibility to your statements. So don't write "alt tags", since there is no such thing as
<alt> tags in any know version of HTML or XHTML. (It's an attribute.)