You need an agency whose metrics align with your business goals (e.g., increased sales, higher customer lifetime value, lead generation, website traffic). Beware of agencies that only focus on vanity metrics like open rates and click-through rates without connecting them to tangible business outcomes. Ask them about their Key Performance Indicators (KPIs) and how they'll report on them.

Past performance is a strong indicator of future results. Look for agencies that can demonstrate their ability to deliver results. Seeing examples relevant to your business helps you understand their creative style, strategic thinking, and effectiveness in your niche. Also, ask if you can speak to any of their past or current clients as references.

A good agency will have a clear, well-defined process. You need to understand how they will work with you, what steps are involved, and what your role will be. This includes how they approach audience segmentation, personalization, A/B testing, and how frequently they'll communicate updates and reports.

Why it's important: Understanding their tech stack helps you assess their capabilities and compatibility with any existing systems you have. Crucially, ask how they maintain high deliverability rates (ensuring emails reach inboxes and avoid spam folders) and their knowledge of email marketing laws to protect your brand's reputation and avoid legal issues.

Clear and consistent communication is vital for a successful agency-client relationship. You want to know who you'll be working with directly, their level of experience, and how often you can expect to receive updates and hold meetings. This helps set expectations for collaboration.

Email marketing effectiveness hinges on compelling content and design tailored to your audience. Inquire about their copywriting and design capabilities, their approach to understanding your brand's unique voice, and how they use data to personalize messages and create highly relevant email experiences.