True cost comparison — not just what the pricing page says
Quick Verdict
Mailchimp saves you 100%
Best for Microsoft 365
Email marketing platform with automation. Free for 500 contacts, then contact-based pricing creates
Best for Mailchimp
Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user pricing where deskto
Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user ...
Advertised
$6
/month
True Cost
$114
/month (typical)
Desktop Apps Require Business Standard
Business Basic ($6/user/mo) only includes web and mobile Office apps. Desktop Word, Excel, PowerPoin...
Copilot AI Add-On
Microsoft 365 Copilot AI is $30/user/mo — separate from all base plans. For 50 users, Copilot alone ...
Compliance Features Require E5
Advanced compliance (eDiscovery, DLP, Information Barriers, Insider Risk Management) require Enterpr...
Teams Phone Add-On
Microsoft Teams Phone System for PSTN calling is not included in any standard plan. Teams Phone Stan...
Email marketing platform with automation. Free for 500 contacts, then contact-ba...
Advertised
$0
/month
True Cost
$113
/month (typical)
Unsubscribed Contacts Count
Mailchimp counts unsubscribed and non-subscribed contacts toward your billing limit. A list of 10K w...
Steep Contact Tier Scaling
Pricing jumps dramatically: 500 contacts = $13.99/mo, 2,500 = $45/mo, 10K = $100/mo, 50K = $350/mo. ...
Pay-As-You-Go Email Credits
Over-limit sends cost extra as email credits. Standard plan allows 12x your contact limit per month....
Advanced Automation Paywall
Free and Essentials include only basic automations. Customer journeys with branching, A/B testing, a...
Mailchimp advertises $0/mo. Microsoft 365 advertises $6/mo.
Mailchimp has 4 documented hidden fees. Microsoft 365 has 4.
Mailchimp confidence: 80%. Microsoft 365 confidence: 84%.
| Metric | Microsoft 365 | Mailchimp | Winner |
|---|---|---|---|
| Advertised Price | $6/mo | $0/mo | Mailchimp |
| True Monthly Cost | $114/mo | $113/mo | Mailchimp |
| Hidden Fee Total | +$107.5/mo | +$113/mo | Microsoft 365 |
| # Hidden Fees | 4 | 4 | Microsoft 365 |
| Confidence Score | 84% | 80% | Microsoft 365 |
| Pricing Tiers | 3 | 4 | — |
| Affiliate Program | No public affiliate program | No public affiliate program (discontinued 2022) | — |
Microsoft 365 advertises $6/mo and Mailchimp advertises $0/mo. However, when you include hidden fees, Microsoft 365 has 4 documented hidden fees adding +$107.5/mo, while Mailchimp has 4 hidden fees adding +$113/mo. Based on true cost, Mailchimp is typically 100% cheaper.
Microsoft 365 has 4 documented hidden fees: Desktop Apps Require Business Standard, Copilot AI Add-On, Compliance Features Require E5, Teams Phone Add-On. These add approximately +$107.5/mo on top of the $6/mo advertised price.
Mailchimp has 4 documented hidden fees: Unsubscribed Contacts Count, Steep Contact Tier Scaling, Pay-As-You-Go Email Credits, Advanced Automation Paywall. These add approximately +$113/mo on top of the $0/mo advertised price.
Choose Microsoft 365 if: Email marketing platform with automation. Free for 500 contacts, then contact-based pricing creates . Choose Mailchimp if: Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user pricing where deskto. The right choice depends on your team size, usage volume, and which features you need most.
This comparison is based on manual research of official pricing pages, terms of service, and user reports. Microsoft 365 data has a 84% confidence score and Mailchimp has 80%. Prices were last verified in April 2026. For the most accurate estimate, enter your specific usage in our calculator.
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