Mailto BCC and CC Parameters: Complete RFC 6068 Guide

Need to pre-fill CC or BCC recipients in your mailto links? This guide covers everything you need to know about using cc and bcc parameters according to RFC 6068.

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Quick Reference

<!-- CC (Carbon Copy) -->
<a href="mailto:primary@example.com?cc=copy@example.com">Send Email</a>

<!-- BCC (Blind Carbon Copy) -->
<a href="mailto:primary@example.com?bcc=hidden@example.com">Send Email</a>

<!-- Both CC and BCC -->
<a href="mailto:primary@example.com?cc=visible@example.com&bcc=hidden@example.com">Send Email</a>

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Understanding CC vs BCC

Parameter	Full Name	Visibility	Use Case
cc	Carbon Copy	All recipients can see	Keep team members informed
bcc	Blind Carbon Copy	Hidden from others	Compliance, archiving, private copies

When to Use CC

• ✅ Keeping managers in the loop
• ✅ Team collaboration where visibility matters
• ✅ Professional courtesy copies

When to Use BCC

• ✅ Sending to groups without exposing email addresses
• ✅ Compliance archiving (auto-copy to records)
• ✅ Privacy-sensitive communications

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Complete Syntax Guide

Basic CC

<a href="mailto:boss@company.com?cc=assistant@company.com">
  Email with CC
</a>

Multiple CC Recipients

Separate multiple addresses with commas:

<a href="mailto:project@company.com?cc=member1@company.com,member2@company.com,member3@company.com">
  Email Project Team
</a>

Basic BCC

<a href="mailto:client@external.com?bcc=archive@company.com">
  Email Client (with Archive)
</a>

Multiple BCC Recipients

<a href="mailto:newsletter@company.com?bcc=subscriber1@email.com,subscriber2@email.com">
  Send Newsletter
</a>

Combined: To + CC + BCC + Subject + Body

<a href="mailto:main@example.com?cc=team@example.com&bcc=archive@example.com&subject=Project%20Update&body=Hi%2C%0A%0APlease%20see%20the%20attached%20report.">
  Contact Team
</a>

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URL Encoding Rules

Special characters must be URL-encoded:

Character	Encoded	Example
Space	%20	?subject=Hello%20World
@	%40	Rarely needed in addresses
&	%26	Use in body text
+	%2B	user%2Btag@email.com
,	%2C	Not needed between emails
Line break	%0A	Multi-line body

Comma Between Emails: Do NOT Encode

When listing multiple emails, use raw commas:

<!-- Correct -->
?cc=one@example.com,two@example.com

<!-- Incorrect (will break) -->
?cc=one@example.com%2Ctwo@example.com

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Email Client Compatibility

Client	CC Support	BCC Support	Multiple Recipients
Gmail	✅	✅	✅
Outlook (Desktop)	✅	✅	✅
Outlook (Web)	✅	✅	✅
Apple Mail	✅	✅	✅
Thunderbird	✅	✅	✅
Yahoo Mail	✅	⚠️ Sometimes ignored	✅

Known Issues

Outlook URL Length Limit

• Outlook has a ~2000 character limit for mailto URLs
• Keep your total URL short, especially with long body text

Yahoo Mail BCC

• Some versions of Yahoo Mail may ignore BCC
• Test before deploying in production

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Real-World Examples

1. Support Ticket with Manager CC

<a href="mailto:support@company.com?cc=manager@company.com&subject=Urgent%20Issue%20-%20Order%20%231234">
  📧 Report Issue
</a>

2. Team Announcement with BCC

<a href="mailto:announcements@company.com?bcc=all-staff@company.com&subject=Q1%20Results">
  📢 Send Announcement
</a>

3. Client Email with Internal Archive

<a href="mailto:client@external.com?bcc=crm-archive@company.com&subject=Proposal%20Follow-up&body=Dear%20Client%2C%0A%0AThank%20you%20for%20your%20time...">
  💼 Follow Up with Client
</a>

4. Conference Speaker Invitation

<a href="mailto:speaker@conference.com?cc=events@company.com,marketing@company.com&subject=Speaking%20Invitation%20-%20DevConf%202025&body=Dear%20Dr.%20Smith%2C%0A%0AWe%20would%20like%20to%20invite%20you...">
  🎤 Invite Speaker
</a>

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Generate Perfect Mailto Links

Manually encoding these parameters is error-prone. Use our Free Mailto Link Generator to:

• ✅ Add multiple CC/BCC recipients
• ✅ Auto-encode special characters
• ✅ Preview the final URL
• ✅ Generate QR codes

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RFC 6068 Technical Reference

From RFC 6068 Section 2:

The “mailto” URI designates an “Internet mail address” for the purposes of message composition… The cc and bcc headers are explicitly allowed.

Allowed Headers

to, cc, bcc, subject, body, in-reply-to, keywords

Disallowed Headers

from, date, received, content-type (and any X- headers)

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Summary

Task	Syntax
Add CC	?cc=email@example.com
Add BCC	?bcc=email@example.com
Multiple CC	?cc=a@ex.com,b@ex.com
CC + BCC	?cc=a@ex.com&bcc=b@ex.com
Full example	mailto:to@ex.com?cc=cc@ex.com&bcc=bcc@ex.com&subject=Hi

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Related Reading

• Why Mailto Links Cannot Have Attachments
• Complete Mailto Syntax Guide
• Mailto Link Generator

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Last Updated: December 2025