7 Best Mailforge Alternatives in 2026

Maildoso is one of the largest standalone cold email infrastructure providers, powering over 400,000 mailboxes and processing 10 million+ emails daily. The platform offers both SMTP-only mailboxes and Combo plans that bundle SMTP with real Google Workspace accounts, giving teams flexibility in how they diversify their sending infrastructure. Maildoso holds a 4.7 G2 rating from 159 reviews and is used by over 5,000 companies.

SMTP pricing scales aggressively with volume: 30 mailboxes for $75/month ($2.99/mb), 70 for $158 ($2.25/mb), 300 for $570 ($1.90/mb), and 10,000 for $12,000 ($1.20/mb). Combo plans mixing SMTP and Google Workspace start at 15+15 for $90/month ($3/mb each). The platform includes one-click integrations with Instantly, SmartLead, and EmailBizon, plus API and MCP access for custom workflows.

The main trade-off is that SMTP mailboxes are not real Google or Microsoft accounts, which can affect deliverability to certain ESPs. Google Workspace is only available in Combo bundles, not standalone. However, for high-volume operations prioritizing cost over account authenticity, Maildoso offers the most competitive bulk pricing in the market.

Inframail takes a unique approach to cold email infrastructure by offering unlimited inboxes at a flat monthly rate instead of per-mailbox pricing. Built entirely on Microsoft cloud infrastructure with dedicated US-based IP addresses, Inframail is designed for agencies and high-volume senders who want predictable costs regardless of how many mailboxes they create.

The Unlimited Plan costs $129/month and includes 1 dedicated US IP address with a cap of 80,000 emails per month. The Agency Plan at $327/month provides 3 dedicated IPs and a 300,000 email cap. Both plans include Inframail's Phantom Redirect technology, which hides domain redirects from ESPs to protect sender reputation, and automated blacklist delisting with a reported 68.3% success rate.

Inframail is Microsoft-only with no Google Workspace support, which limits flexibility for teams that want to diversify across ESPs. The flat-rate model can be expensive for smaller teams who only need 10-20 mailboxes, but it becomes extremely cost-effective at scale when running 100+ inboxes per domain.

Zapmail is a cold email infrastructure provider specializing in real Google Workspace accounts that come pre-warmed and ready to send from day one. With over 1 million mailboxes set up across 330,000+ domains, Zapmail has built significant scale in the space. The platform includes AI-powered tools like Domain Genie for smart domain selection, Smart Mailbox Namer for realistic email personas, Persona Snapshots for profile customization, and Zapbox AI for workflow automation.

Pricing follows a tiered structure: Starter at $39/month includes 10 Google Workspace accounts ($3.90 effective per mailbox), Growth at $99/month includes 30 accounts ($3.30/mb), and Pro at $299/month includes 100 accounts ($2.99/mb). Extra mailboxes cost $3.50, $3.25, or $3.00 respectively depending on your tier. API access is only available on the Pro plan, which can be limiting for teams that want to automate provisioning.

Zapmail holds a 4.5 TrustPilot rating and claims 50,000+ businesses served. However, some users have reported India-based IP addresses on accounts instead of US IPs, Microsoft 365 instability issues, and a strict no-refund policy. The platform lacks comprehensive domain monitoring comparable to InfraGuard-style solutions.

Instantly is a full-featured cold email outreach platform, not just an infrastructure provider. It combines email sequencing, AI-powered warmup, a B2B lead database with 160M+ contacts, a built-in CRM, inbox placement testing, and email verification into a single ecosystem. With a 4.8 G2 rating from 3,200+ reviews, Instantly has the largest community in the cold email space and is often the first tool teams adopt.

The Growth plan starts at $47/month and includes unlimited email accounts, 1,000 active contacts, and 5,000 emails per month. Hypergrowth at $97/month bumps that to 25,000 contacts and 100,000 emails. The Light Speed plan at $358/month adds the SISR system for inbox rotation. Lead database access starts at $47.99/month separately. Email accounts can be purchased as add-ons or connected from external infrastructure providers.

The key trade-off with Instantly is cost and control. Per-mailbox infrastructure costs are significantly higher than dedicated providers, and you lose granular DNS and domain management control. Mailboxes purchased through Instantly are locked into their ecosystem, making it harder to switch sequencers later. For teams that already have a sequencer, pairing a standalone infrastructure provider with Instantly offers better value and flexibility.

Mailreef is a managed cold email infrastructure provider that takes a white-glove approach — each customer gets a dedicated server with a dedicated IP address and unlimited free inboxes on that server. Rather than self-service provisioning, Mailreef offers live delivery consulting, spammer screening to protect shared reputation, and hands-on support for DNS configuration and deliverability optimization.

Mailreef claims to handle over 100 million emails per month across its customer base with 0 blocked mailboxes and 99.9% uptime. The platform integrates directly with SmartLead and Instantly for sequencing. Pricing is not publicly listed and requires contacting their sales team, which positions Mailreef as a premium managed service rather than a budget self-service tool.

The managed model works well for teams that want expert guidance and do not want to handle infrastructure themselves. However, the lack of transparent pricing, limited self-service controls, and contact-sales requirement make it harder to evaluate and onboard compared to platforms with published rates and instant provisioning.