What are cloud-based email services?

Cloud-based email services include both mailbox hosting (Google Workspace, Microsoft 365, Zoho Mail, Rackspace Email) for users to send/receive personal email, and cloud sending services (AWS SES, SendGrid, Mailgun, Postmark) for applications to send transactional and marketing email at scale. Different problems, different tools.

What is the difference between Google Workspace and AWS SES?

Google Workspace gives users mailboxes (inbox, send, receive) for human-to-human email. AWS SES is an API/SMTP service for applications to send transactional and bulk email programmatically — no mailboxes, no UI for end users, just an endpoint. Most companies need both for different purposes.

Can I use Google Workspace for marketing emails?

No, not at any scale. Google Workspace caps sending at 2000 messages/day per user via SMTP and the Gmail API. It's designed for human conversation, not bulk sending. Use a dedicated cloud sending service like SES, SendGrid, Mailgun, or Postmark for marketing and app email.

Are cloud email services secure?

Major cloud email services (Workspace, M365, SES, SendGrid) provide TLS 1.2+ for transport, SPF/DKIM/DMARC support, and SOC 2 compliance. Security depends on configuration — enable 2FA, use scoped API keys, configure DMARC at p=reject. The infrastructure is secure; misconfigured deployments aren't.

What is the cheapest cloud email service?

For mailboxes: Zoho Mail ($1/user/mo) or Google Workspace Business Starter ($7/user/mo). For sending: AWS SES at $0.10 per 1000 emails. Free tiers: Google Workspace via Gmail for personal use, Brevo (300/day) for app sending. Cloud email is generally cheap — the cost is configuration time.

Cloud-Based Email Services: Sender Comparison

"Cloud-based email services" is a category label that covers two completely different jobs people conflate. Mailboxes for users (Google Workspace, Microsoft 365) and sending services for applications (SES, SendGrid, Mailgun). They use the same underlying SMTP protocol but solve different problems and you need both.

The cluster around cloud based email services and cloud email solutions includes both intents. This guide separates them cleanly and rates the major options for senders.

Two Different Jobs

Job	What it does	Examples	Cost model
Mailbox hosting	Users send/receive email	Google Workspace, M365, Zoho, Rackspace	$/user/month
Sending services	Apps send bulk/transactional email	SES, SendGrid, Mailgun, Postmark, Resend	$/email or volume tiers

A company typically needs both. Google Workspace for employees to email customers and each other. SES (or similar) for the app to send password resets and the marketing team to send campaigns. Using Workspace for the second job breaks at low volume.

Mailbox Hosting Options

Google Workspace

The default. Business Starter ($7/user/mo) gives custom domain Gmail, 30GB storage per user, Meet, Calendar, Drive basics. Business Standard ($14/user/mo) adds shared drives and recording. Enterprise tiers add advanced controls.

Strengths:

Best mail client (Gmail)
Strong spam filtering for inbound
Reliable inbound and outbound delivery for human-to-human email
Mature admin console

Sending limits: 2000 messages/day per user via SMTP relay and Gmail API. This is fine for users emailing each other and customers. Not fine for application or marketing email.

Microsoft 365

Microsoft's competitor. Business Basic ($6/user/mo) gives Exchange mailbox, Teams, Office web. Business Standard ($12.50/user/mo) adds desktop Office apps.

Strengths:

Better fit for Windows-heavy organizations
Outlook desktop client (still preferred in many enterprises)
Strong calendar/Teams integration

Sending limits: 10,000 messages/day per user via SMTP. Still not enough for bulk or app email, but higher than Workspace.

Zoho Mail

Budget option at $1/user/mo for the base plan. Mature product, decent admin features.

Best for: cost-sensitive small businesses, non-Google-Office environments.

Rackspace Email

Older entrant, $1.99-$3.99/user/mo. Email-only, no productivity suite. Niche fit for businesses that don't want Workspace or M365 overhead.

Cloud Sending Services

For applications, marketing, and high-volume needs, use a dedicated sending service. These have no mailbox UI — they're send endpoints.

Provider	Volume model	Free tier	Strength
AWS SES	$0.10/1K	62K/mo from EC2	Cheapest at scale
SendGrid	Volume tiers from $19.95/mo	100/day	Hybrid marketing + API
Mailgun	Volume tiers from $35/mo	100/day for 30 days	EU residency, high vol
Postmark	Volume tiers from $15/mo	100/mo	Best transactional deliverability
Resend	Volume tiers from $20/mo	3K/mo	Modern API, DX
Mailersend	Volume tiers from $30/mo	3K/mo	Templates + API

See free email API comparison for deeper breakdown.

Practitioner note: I see startups try to send all their email through Google Workspace because "we already pay for it." Within months they hit the 2000/day limit on the noreply@ account and start having password resets fail silently. Setting up SES or Postmark for app email takes 2 hours and saves the inevitable incident.

Hybrid Mail Stacks

Most companies end up with at least two services:

Google Workspace for employee mailboxes (the team uses it for human email)
AWS SES, Postmark, or SendGrid for application email and marketing
Sometimes a third for marketing specifically (Klaviyo, Mailchimp) if marketing volume is high

Subdomain strategy for the sending services:

mail.example.com for marketing campaigns
send.example.com for transactional/app email
example.com for employee email (your Workspace/M365 domain)

This keeps reputation isolated. Marketing list issues don't take down password resets. See enterprise email marketing guide for the broader architecture.

Receiving via Cloud

If you need inbound parsing — apps that receive email at addresses on your domain (support@, reply@) — your options:

Mailgun Routes — parse and POST to webhook
SendGrid Inbound Parse — same
Postmark Inbound Streams — clean API
AWS SES + SNS/S3 — DIY parsing on SES inbound, dump to S3 or trigger Lambda
Mailersend Inbound — newer offering

Configure MX records to point at the provider's inbound infrastructure. Your application receives parsed messages.

Email Security Layer (Inbound)

For enterprise inbound mail filtering beyond what Google/Microsoft include:

Proofpoint — enterprise email security, anti-phishing
Mimecast — secure email gateway
Barracuda Email Security — gateway + post-delivery protection
Abnormal Security — ML-based behavioral filtering
Microsoft Defender for Office 365 — built into M365 enterprise tiers

These sit between the internet and your mailbox provider, filtering phishing and BEC attacks. Most senders don't need these — they're for organizations being actively targeted.

Cost at Real Volume

Sending 1M emails/month:

Service	Monthly cost
AWS SES	~$100
Postmark	~$700
SendGrid	~$540
Mailgun	~$500
Resend	~$400
Google Workspace	Not possible — hits rate limits

SES wins on cost. Postmark wins on transactional deliverability. SendGrid wins on hybrid marketing + transactional. Pick on fit, not just price.

What to Avoid

Sending application email from Google Workspace SMTP — rate limits, no per-message reputation, support issues
Running your own mail server for sending — manageable for inbound, painful for outbound. See self-hosted SMTP options if you must.
Combining marketing and transactional on one shared IP — complaint rate from marketing tanks transactional delivery
Free tier email for production at any real volume — works for prototypes, breaks for products

If you need help architecting a cloud email stack across mailboxes and sending services, book a consultation. I do email infrastructure design for SaaS teams, agencies, and ecommerce operations.

Sources

v1.0 · May 2026