Many groups I know use their websites to solicit donations. This means they receive money coming in from other states where the 501(c)(3) group is not registered to solicit. Because much of their solicitation was done online, through newsletters, e-newsletters, or via e-mails, could they get in trouble for not registering in every state?
Yes. The National Association of State Charity Officials has taken the position that “passive” website solicitation, where the charity does not actively try to drive traffic to the website and merely accepts donations from people who find it, does not create the need for registration in additional states. But where the organization tries to get people from other states to go to the website to contribute, registration is required. It sounds like the process you describe of sending newsletters, e-newsletters and e-mails to others in other states, if those messages ask for funds or drive traffic to the site that asks for funds, would generate the requirement to register.
Even if there is no active development in other states and the organization's website is truly passive, any good development person will thank a donor and sooner or later ask for more. As soon as that request goes to another state, it will technically trigger the need to register in that state if registration is required.
Interested in learning more about charitable solicitation registration? Consider purchasing our pre-recorded webinar - State Charitable Solicitation Statutes: Everything You Wanted to Know But Were Afraid to Ask.