MailStrike vs SendScale Email Warmup

MailStrike is an email deliverability platform for mailbox warming, placement testing, and seed lists for B2C senders. AI personas create and reply to email threads using a company's description and industry. Its warming network exchanges threads among business mailboxes while excluding spammers, free-mail senders, and dodgy sites. On connection, the service checks SPF, DKIM, DMARC, and MX records and identifies missing values. Google Workspace and Microsoft 365 connect through OAuth; other providers use IMAP and SMTP with an app password. Warming reaches full volume by day 21 and then continues at a maintenance volume. Seed lists monitor placement and can interact with messages; setup requires one DNS TXT record for domain verification. A free deliverability test reports inbox, promotions, or spam placement and scores spam signals without requiring a card. MailStrike runs on the web and through an API. Paid plans start at $18/mo (annual); there is no free plan, but a free trial is available.

SendScale Email Warmup is a service for warming email accounts and building sender reputation for cold outreach. It connects Google Workspace and Microsoft 365 inboxes through OAuth, then uses AI to exchange unique messages between accounts in a private network SendScale says contains more than one million inboxes. The service says its system opens and scrolls through messages and replies in human-style language. If a warmup email lands in spam, SendScale says it moves the message out, marks it important, and replies. A dashboard tracks daily sends and replies, spam-versus-inbox placement trends, and readiness. SendScale recommends 14 days for new domains and says the dashboard indicates when warmup is complete; warmup can continue at lower volume while campaigns run. The service also describes account rotation for load balancing and a Master Smartbox for consolidating replies. Its free plan includes pre-warmed inboxes, warmup tools, in-product conversational guidance, and campaign access. Paid plans start at $28/mo billed annually. The privacy policy places database servers exclusively in the European Union and describes industry-standard security measures.