Angel investors play a crucial role in any startup ecosystem, by making bets on companies at their earliest stages—to help them develop prototypes, get through beta phases, and attract early customers and the next level of investors. It seems every time a Boston-area company announces it has landed some seed funding, a mysterious crop of angel investors is behind it. So we wanted to take a closer look at some of these key players around town—where their careers have taken them, what sectors they’re keeping an eye on, and how they go about deciding when to write those checks.

Read more: Top Angel Investors of New England: An Innovation Slideshow

An intriguing Boston-area tech company is going public after more than 10 years—and it’s not too late to shake things up in its market. I’m not talking about Zipcar (NASDAQ: ZIP), which had its long-awaited IPO a couple weeks ago. I’m talking about SMTP, a pioneering e-mail software firm based in Cambridge, MA.

Yes, the company with the famously boring name—it makes software for e-mail delivery management and marketing—is going public today. It’s not debuting on the Nasdaq or New York Stock Exchange; rather, trading of SMTP’s stock begins this morning on the over-the-counter bulletin board (OTCBB: SMTP). Companies that trade over the counter generally don’t have to meet the same SEC filing requirements as those that trade on the more regulated stock exchanges; it can also be harder for investors to trade OTC shares, partly because buyers and sellers must arrange their trades directly.

Read more: Semyon Dukach, the MIT Blackjack King, Takes SMTP Public in Latest Effort to Fight the Power