# RFC 7293: The Require-Recipient-Valid-Since Header Field and SMTP Service Extension

> request for comments publication

**Wikidata**: [Q47248815](https://www.wikidata.org/wiki/Q47248815)  
**Source**: https://4ort.xyz/entity/rfc-7293-the-require-recipient-valid-since-header-field-and-smtp-service-extension


## References

1. RFC Index
2. DBLP Dataset 2021-01-02