A brand-new sending domain has no reputation with Gmail, Outlook, or any other mailbox provider. If you send a large batch of email the day you set it up, even with perfect SPF, DKIM, and DMARC in place, a good chunk of it lands in spam. The fix is to ramp volume gradually over one to two weeks while watching how recipients react, so mailbox providers build up trust in the domain before you send at full scale.
This isn't a Flashcloud-specific quirk. It's how every major mailbox provider works: reputation is earned per sending domain (and per sending IP), and it's earned slowly.
Why new domains land in spam
Mailbox providers use domain and IP reputation as a primary spam signal. A domain with no sending history looks identical, statistically, to a domain someone just registered to blast spam from. Providers respond by filtering cautiously: low initial deliverability, more spam-folder placement, sometimes outright deferrals.
Authentication records fix a different problem. SPF and DKIM prove the email really came from your domain and wasn't spoofed. They don't prove your domain is trustworthy, that takes time and consistent behavior. Both matter, but they solve different problems, and warming up only addresses the second one.
Sudden volume spikes make it worse. A domain that sends five emails a day and then suddenly sends five thousand looks exactly like a compromised account or a spam run, even if every recipient asked for the message.
The volume ramp
The core idea: start small, increase gradually, and let real engagement build trust before you scale up.
- Days 1-3: Send to your most engaged contacts first, people who open and reply reliably. Keep volume low, a few dozen to a couple hundred messages a day depending on your list size.
- Days 4-7: Increase gradually, roughly doubling volume every two to three days if opens and replies stay healthy. Keep prioritizing engaged segments over your full list.
- Week 2 and beyond: Continue the ramp until you reach your normal sending volume. Mix in less-engaged contacts slowly rather than all at once.
There's no universal formula, exact numbers depend on your list size and the receiving providers involved. But the pattern holds everywhere: gradual, consistent, monitored. A domain that sends a steady, growing volume with strong engagement earns trust faster than one that sends sporadically or in large bursts.
If you're moving from another email service to Flashcloud-hosted email, treat the new domain as unwarmed even if your old sending history was excellent. Reputation generally doesn't transfer between providers or IP ranges. Start the ramp from day one.
Engagement is the real signal
Volume alone won't build reputation, mailbox providers weight engagement heavily: opens, replies, and messages moved out of spam into the inbox, all count as positive signals. Deletes without opening, spam reports, and high bounce rates count against you and can undo a week of careful ramping in a single send.
A few practical habits during warmup:
- Send to people who actually want the email. Warming up on a purchased or scraped list is close to guaranteed to fail.
- Clean your list before you start. Remove addresses that have bounced before or never engaged.
- Watch bounce rate. Anything climbing above 2-3% during warmup means your list has a hygiene problem, pause and clean it before sending more.
- Avoid content that trips spam filters: excessive links, all-caps subject lines, spammy phrasing. See the content-audit section of why are my emails going to spam for specifics.
If you're sending through a third-party platform (Mailchimp, SendGrid, and similar), check whether it has its own warmup guidance or automated warmup features for the sending domain. Many do, and it's worth following their platform-specific ramp on top of the general principles here. Whichever platform you use, make sure its SPF and DKIM are correctly added to your DNS, covered in SPF and DKIM setup, since a warmed-up domain with broken authentication still lands in spam.
Add DMARC once warmup is underway
DMARC tells receiving servers what to do with mail that fails SPF or DKIM, and it gives you visibility into how your domain is being used. It isn't configured automatically on Flashcloud, you add it yourself as a DNS record. It's worth adding once your baseline authentication is confirmed working and warmup has started, rather than waiting until you hit a deliverability problem to think about it. Start with a monitoring policy before moving to anything stricter, so you can see the reports without risking legitimate mail getting blocked.
If you're setting up Google Workspace instead
If you're routing your domain's email through Google Workspace rather than our hosting-based email, the same warmup principles apply, Google's reputation systems work the same way. Follow the DNS steps in using Google Workspace with your domain to get MX, SPF, and DKIM configured correctly first, then ramp volume the same way described above.
When to contact support
Warmup itself is something only you control, it depends on your list and sending behavior, not your hosting setup. But open a ticket from Support in the portal if you suspect your domain or mail server IP has been blacklisted, if DKIM records aren't showing up in DNS when they should be, or if legitimate warmup-stage mail is bouncing in a way that looks like a server-side block rather than a recipient-side spam filter. Support can check server-side sending logs and blacklist status that you can't see from your inbox.