Do you think direct email marketing works for selling professional services?

And what is your opinion on bulk email marketing and would you ever use it for promoting/selling your business service?

I've done biz dev in professional services. I also tend to hire a lot of professional services providers for companies I work with. E-mail marketing and other shove type of marketing does not work. PERIOD! To sell professional services effectively, one must invest a lot in building strong business relationships. It is all about face time, earning trust, doing phenomenal job, and letting your reputation do the selling. This reputation is what gives you the pricing power and referrals.

I get a few of those every day and they go to the trash very quick.
Unless you are specialized on something unique, I don't see any success on it.

You better bet is pinpoint companies that can benefit from your services and call them directly.

Let me give you an example:

I was working for a online directory of industrial manufactures. Most of the companies have a web site that were advertising in the directory, but most of these sites were designed poorly.

So what someone I know did was calling them directly and offer them to redo their site for a reasonable price. He had some good examples of sites he did for a few other companies in the directory and he made a living out of it.

The secret is: niche market.

E-Mail marketing ends up in the junk folder, with professional services, you are better off making the phone calls

I disagree with all other advice. I have been running marketing campaigns on a 6-digit budget, as well as for a non-profit cause, for many years. E-mail is still the best way to reach people.

Of course, spam is a terrible approach. But if you want people to take action, their inbox is still the most read and trusted place. The secret: the e-mail must come from a source that they trust.

How is that possible? You need to find out what newsletters people in your industry read. Surely, your target market subscribes to a few of these. Then approach the authors of those newsletters. Some will have a way to accept a sponsored message. Others will curate their mailings very carefully, but if you convince them of the value of your offering, they may include you.

Bottom line: it's all about trust and value. If your product is junk, then no one will agree to talk about it. But if you really have something interesting, you just need to convince a handful of gatekeepers in order to get exposure to a wide audience.