It's been pointed out to me that Campaign Monitor did address this for responsive emails in 2013, but the documentation hasn't been updated...And I've been relying on the documentation as authoritative.

As this post continues to make its rounds in the community, it seems to have become something of a 'state of the email developer market' conversation. I'd like to chime in with my perspective, too: There are developers out there, like myself, who appreciate email coding work! For all its challenges, email design and development is also focused, effective work that gets built, gets sent, and gets results on a reasonable timeline.

Your points on wanting to keep the work in-house are appreciated. I think it's worth considering freelancers, particularly those who are looking to have some steady, repeat business in their client roster. Those of us charging market rates may appear more expensive than in-house or staffing firm talent, but we're covering the business overhead that's elsewhere on your company's books, and are typically self-starters who know how to manage our role and deliverables in a project, which translates into efficient turnarounds and billable time. A minimal retainer is often effective in keeping a skilled freelancer in the loop who can help keep things on track when you're in a pinch internally, or bring skills to the table that it's not worthwhile to pay a salary to maintain in-house.