Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="----------C61031FF2231ECF0"

This is a cryptographically signed message in MIME format.

------------C61031FF2231ECF0

Content-Type: text/plain; charset=koi8-r

Content-Transfer-Encoding: 8bit

Текст Письма

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Content-Type: application/pkcs7-signature; name="smime.p7s"

Content-Transfer-Encoding: base64

Content-Disposition: attachment; filename="smime.p7s"

Content-Description: S/MIME Cryptographic Signature

MIIFPQYJKoZIhvcNAQcCoIIFLjCCBSoCAQMxCzAJBgUrDgMCGgUAMAsGCSqGSIb3DQEHAaCCAyow

...

------------C61031FF2231ECF0--