How To Choose The Right Email Marketing Agency

For the last two-plus decades, marketing professionals have been creatively and effectively using email marketing to drive leads and build brands. From business to consumer to nonprofit audiences, we’ve maximized that messaging potential, to the tune of a $37 to 1 ROI via this one channel alone. 
So if you’re ready to use email, but you’re not a professional marketer, how do you find the right agency partner to help you maximize that potential?
Asking for Referrals
Most small businesses start by asking their colleagues for referrals of good sources they know for digital or email marketing, and that’s certainly a place to start. Keep in mind, though, that just because an agency has a great relationship with your colleague does not mean they are the right fit for you. Make sure their work style, messaging style and technology stack is in alignment with your current setup and goals. In addition, be sure to review their work for the types of emails you’re looking for. After all, they might produce a great newsletter for your colleague, but can they send the right kind of ecommerce email to bring in sales from your audience? Be sure that the agency you’re considering is a personality, technology and style match for your organization.
Industry Specialists
Often organizations will seek out a specialist in their industry for their program. Sometimes, this makes a lot of sense. If you have a very unique offering that requires expertise and you don’t have the in-house capability to provide contextual guidance for your communications, then you may want to lean on a provider who can tell your stories from the right perspective. More often than not though, organizations can lean in internal resources for industry expertise, and look for the agency to provide email expertise. 
For example, if you have a sales or marketing team who can be available for copy editing reviews, interviews about client stories, or general strategic planning support, you can lean on an agency that provides solid storytelling, technical expertise in the channel, and support for all the parts of the work that you can’t do well alone. This especially works well for organizations for whom industry specialists are hard to find, very costly, or just nonexistent. 
Choosing the right agency (or in some cases freelance help) is a very personal decision. My fellow Mailchimp Partners also offered some important considerations...

Credentials - in the Mailchimp world, are they a Partner or a Pro-partner?... Have they completed the certifications?...  and i'd then test their own systems... if you can't do a decent system for yourself, how can you do it for someone else?... does your form work?... do you have an automation?... is it well written?.
All of this matters before I even have a conversation with them...
Robin Adams, Founder

I'm looking for someone I "vibe" with. (I hate saying it that way, but it's kind of true. Do they have similar concerns, way of working, and values what I do.) Then I look for recent experience and how long they've been in business.
Amy Hall, Email Marketing Strategist and Certified Mailchimp Partner

I love this saying… If you had a knee problem, would you rather go to a doctor or a specialist knee doctor? I think the same thing goes for choosing someone to work with. Make sure there’s a fit. Do they understand your problems and your goals, do they have experience in your niche.
Doug Dennison, CEO & Co-founder

When looking for professional email marketing services, you'll want to review the agency or freelancer based on multiple factors. First of all, you'll want to work with a service provider who you get along with. Chemistry is key. You'll also want to make sure they've been successful with other brands that have similar goals. Ask them to provide example briefs, reports, and other documents you will require, ask for references, and ask why they are no longer working with previous clients. If everything checks out, enter into the agreement with a trial period to make sure you mesh, and if not, give the agency or freelancer a chance to address your concerns. Once you have a solid working relationship then you're well on your way to achieving your email marketing goals.
Adam Q. Holden-Bache, Director of Email Marketing

Asking for work samples or a portfolio is one of the smartest things a business can do when looking for an agency or freelancer. If an agency can provide some beautiful and diverse samples of work, it will really show what they're capable of. I also think it's important to see what certifications they have. Are they a Mailchimp Partner (wink, wink) and do they have any official certifications from that platform? And lastly, how long have they been in business is a good indicator of how experienced they are. 
Emily Ryan, Co-Founder and Email Strategist

I look for them on LinkedIn, seeing if we have common contacts (that’s why I almost never accept contact requests on LinkedIn by people I don’t know anything about); I read their social posts, their website, their “digital footprint”; I ask my closest friends and colleagues whether they know them: having worked in training and being an event organizer and community manager, it’s highly probable that we have some mutual acquaintances.
And of course, I subscribe to their and their client’s newsletters, to see how they work!
Alessandra Farabegoli, Digital Strategist

For both I'm looking for past experience and examples they can show. When hiring developers we have a test we do and I've sometimes asked, even paid, them to do that test before I use them.
Glenn Edley, Director & Email Strategist