This is a post from a member of the Freelancers Union community. If you’re interested in sharing your expertise, your story, or some advice you think will help a fellow freelancer out, feel free to send your blog post to us here.

There are dozens of reasons why you might find yourself in need of an email address. Perhaps it's to send a post-interview thank you, or to ensure that an inquiry isn't lost in the general email shuffle. All you need is a search engine and a few strategies.

Guess!

Most emails follow: (first name).(last name)@(company.com). So if you are looking for Billy James, you could first try billy.james@hiscompany.com. You might also try using underscores between names, removing the last name, or adding hyphens. As lots email addresses are formatted this way, it's a good first move.

Search Bing

Enter “@domainname.com” in the Bing search bar and see every available email address related to that domain pop up. Note: this technique won’t work in Google because Google uses the @ signs for social tags.

Try Twitter’s advanced search

If you need an email address to perform a reverse email lookup, you can certainly ask someone for it on Twitter. But people sometimes enter their email address in their tweets by using “at” instead of the @ sign and “dot” instead of the period. So if you go to Twitter Advanced Search and enter “at dot,” you will see any posts come up where those two words are used.

Use LinkedIn

If you aren’t connected to the person you'd like to contact, you can still send them a private message asking for their email address. If you are connected, just click on their profile and go to Contact Info.

Check WHOIS Data and other online tools

Checking WHOIS is not 100% reliable as because people often pay for domain privacy. But in some cases, you might be able to look up a domain or name and find the email address.

If your subject has a website or blog and offers signup, do it. This will probably give you their email address at confirmation. Otherwise, use the generic contact form on their website to request an email back.

Ben is Chief Security Officer at InfoTracer and an author of guides on cyber security.