What am I talking about when I refer to digital professionalism? This is not the professionalism that you show to your clients, which many, including me, would argue is the most important; this is how you present yourself digitally. I will mainly talk about website and email, but there are measures you can take with any social media you use also.
Whether it is on the back of a vehicle, a website, flier, business card or in the email you send to someone, the ways you give for people to contact you says a lot about your organisation and may influence whether someone will want to deal with you.
Website
Thankfully this is getting rarer, but I do still see website advertised that are essentially free web spaces on the back of the internet service provider or one of the template providers that lets you have a free website using their name and your username. A UK web domain costs less than £11 per year so not a lot to get a professional web address. You need to host it and I do recommend paying for some basic hosting that usually includes some ways to create your site with minimal technical skills, one or more email accounts and even the domain for the first year. There are free hosts out there but you do get what you pay for and you may have to test a lot before finding one that doesn't cause a problem for your website in one way or another.
Perhaps you have your own domain that reflects your business well, uses a good responsive template, but email costs extra so you stuck with Gmail, Hotmail, Yahoo or the email provided by your Internet Service Provider. What does this say about your organisation? For the sake of a few pounds a month to get a single mailbox for your business or charity, you're using a consumer level email account that you might even use for home as well. You might even be able to get one or a small number of mailboxes included with your website hosting, with a friendly webmail interface and instructions to add to your phone, tablet or desktop email client. You're also missing out on building your brand image in peoples' mailboxes; why should you advertise Gmail or Hotmail when operating your business?
Next, lets assume you have an email address that matches your domain. Good start. But to save money again, the email is forwarded to your personal mailbox and you reply to that email from your personal mailbox. It's possible to have multiple email accounts on a portable device and have the webmail accessible on your computer browser. Why is this important? If a potential customer sends a message to one address but receives a reply from another address then firstly it sends a message about professionalism but secondly they might wonder if it is actually you responding to them of it the message has been intercepted somehow.
Conclusion
To finish with I'm going to give you an extreme example that I've actually come across, though I'll not name names. A small UK business owner had an abbreviated version of their business name at the front end of an AOL address. Bad enough, you may think after reading the text above. He then used this account for official emails for a registered charity he volunteered for. He carried on using this email address for the registered charity (and who knows what personal reasons) after he sold the business.