Keila is a newsletter tool, not a finance system despite this listing's category. Build a small consent-based test list, create a campaign, and send it through the delivery service you would actually use. Inspect email rendering, personalization, bounce handling, segmentation, and unsubscribe behavior.
Before moving subscribers, verify consent records and a clean contact export. Self-hosting also means owning deliverability, sender authentication, updates, and backups. Compare the complete operating workload, not just the editor.
Akousa