Structuring information for business event invitations on HTML emails

Today I was reviewing the structure and hierarchy of information for our HTML event invitations. Business sponsors of events tend to think that absolutely everything is relevant. Some of them would include several screenfuls of text if only we'd let them.

But of course we can't. Clutter kills impact, and people never care as much as we'd like to think. So we need to be as brief as possible.

So - what are the key points when it comes to invitations? The only information which needs to be featured prominently and "above the fold" is the absolute essentials:

1. Event title - should be descriptive enough to give recipient some basic idea of the event's nature. This should be reflected both in the subject line and prominently within the body. We want all of our recipients to read this line, but some of them will then "drop off" immediately, as they may be simply not interested in the topic...
2. Date/time/location - this key logistical information should also be immediately visible, to save the trouble of reading further for those recipients who may be interested but are unable to attend.
3. Optional - additional brief description. If you think it will add value, expand your descriptive text, but keep it very brief and ensure it only covers really key selling points, for example, if one of your speakers is a star.
4. Call to Action - RSVP. This is the most important part of the email, and it should stand out compared to other elements.

I think this is it! Everything else is optional in my opinion, and should be kept apart from this main section.

The next layer of information which is frequently included to invites is logistical details such as the programme, venue address/map.

But I think these are only really relevant to those who accept the invitation, so they should be segregated from the main invitation area. Alternatively, they could be housed on a separate landing page and hyperlinked to the invite email. Finally, you could try including them on a separate confirmation email sent to those who RSVP'd as attending.