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Direct Mail:Specifications and limits

Last Updated:May 27, 2026

Direct Mail enforces limits on email domains, sender addresses, daily quotas, and attachments.

Limits

Item

Description

Email domains

5

Sender addresses

100. Cannot be edited. Up to 10 can be deleted per month.

Daily quota

2,000 emails per account by default. Adjusted based on credit rating.

Monthly quota

Daily quota × 30

Email tags

Up to 500. Each tag is limited to 128 characters.

Recipient lists

10

Addresses per recipient list

Up to 10,000. The actual limit also depends on the daily quota.

Templates

100

IP protection

10 IP addresses or IP address segments

Free email quota

2,000 free emails per account in total. Up to 200 per day.

Data statistics

Real-time query by sender address and email tag.

Attachments

Supported only for SMTP. The console and API do not support attachments.

Maximum total email size: 15 MB. Up to 100 attachments per email.

The 15 MB limit applies to the total SMTP payload. Base64 encoding increases size by at least 1.5x, so keep attachments under 8 MB. For larger files, use hyperlinks instead.

Recipients per call

SMTP: 100 recipients

API:

SingleSendMail (100 recipients), BatchSendMail (1 recipient list)

Console: 1 recipient list

Console email template

Email title: 256 characters

Email body: 1 MB

Console recipient list variables

`UserName`: 75 characters (50 or fewer recommended). `NickName`, `Gender`, `Birthday`, `Mobile`: 25 characters each.

Data query

Data is retained for 1 month.

Sending frequency

Three ways to send emails.