Interesting comments and feedback. I agree for the most part with the general feelings on this matter - I wasn't thrilled when I sent a test email to myself to find the automated footer (and with no means of editing it). But I also think that there's a little bit of over reaction to the "free" component.
(As a side note, whenever you're testing a new system, I would suggest setting up a test user with a test email of your own and try each of the features on yourself as a guinea pig - that way you're not suddenly shocked or surprised by something your clients have or haven't received.)
I do agree that it will target the emails to end up under spam folders (which is incredibly inconvenient) and I do agree that a modified wording for it would be more desirable. As Giuliano suggested, "Sent by bitrix24.com - CRM trusted by almost 1 million organizations worldwide" is very professional. A slight better stylization of this line would be better too - it comes through as a larger, kind of yucky text and looks like a kid added it lol. It would be nice if it at least looked a little better - a slightly smaller font, italics, type of thing.
On the flip side, there are always work arounds for companies that think outside of the box... why not add your own signature to the bottom of your emails? Then below your regular info and above the Bitrix info say something like: "We are an innovative company who are always on the lookout for new tools for businesses. As indicated below, we are currently working with a complimentary introductory option to give us the ability to offer our own opinions and recommendations to other businesses. We'd love your feedback regarding your experience with this particular system."
If necessary, down the road you could even modify it to say something like: "We have been so impressed with the no cost version of this system that we have opted to stay with it. We believe in a budget well spent and have found that we don't need the additional features within the paid versions. We're pleased to announce that this choice means that we won't have to implement a price increase on our products or services this year!" (type of thing)
Perhaps not 100% ideal for every business, but something along those lines will be openly accepted by most clients in most industries. Free tools and open source options aren't anything new and it's probably not a bad idea for businesses to test out free options of a product before jumping in both feet and spending a ton of money (though to be honest, the prices of Bitrix24 are very affordable compared to most systems I've been researching). It's also fair to assume that MOST businesses looking to use the free version are smaller businesses with smaller teams - there's nothing embarrassing about being economical and selective on where the budget is spent. If a multi-million dollar corporation is trying to use this as a free tool and complaining about the footer, well, shame on you lol.
Perhaps the management of Bitrix24 and the Free version users could look to meet in the middle? A minor change in the mandatory wording and tweak to the stylization of it by management... combined with an added custom footer by the user that takes the edge off it... Perhaps Bitrix24 could even provide a dedicated field where this add-on to the footer could be included?