How to read Email Headers
Received: by 2002:a17:906:742:b0:958:803f:dba7 with SMTP id z2csp1282371ejb; Sun, 7 May 2023 03:23:01 -0700 (PDT) X-Received: by 2002:a17:907:3ea8:b0:953:37d9:282f with SMTP id hs40-20020a1709073ea800b0095337d9282fmr6314816ejc.38.1683454980797; Sun, 07 May 2023 03:23:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1683454980; cv=none; d=google.com; s=arc-20160816; b=xDzBzWnVyNz4LCCHfiY4SF6+U0K+ZelOP4Edng+qrV2xqznNzeh62m0pu+sW247ZaF KOrw/BylljK296K6mj7hfDgSD4aHP+7JCMngi/+J2cw8gHe0WVYqBvK3tsk/EbZ01a2b V4NbzfnkLfDX6ZXBWHorojp9U9DFCPzRFaKrlqFYyNOcTX3EK4jiyN0XNaC4oQS/Yw7A XZOJPSdPKsIX178BtSa2Vley+B+vsrpG+WpS65R1ywQsko/IXOOG1QgsYm74MEG7x67B YTVYsG2CFSdi1HBWrPML/KZj4rPg9l1RCII3xbYj72txBg17Bvs2rai2ZyJojfr4kWOE kQbg==
Basic Email Headers
It's kind of log of all the IP addresses through which the message was delivered to the final destination. This header is especially useful in case of any errors, because with it you can follow the whole path from beginning to end.
This header specifies the address where undelivered messages should be returned to. This is usually the SMTP address for bounce processing.
This is the email address to which the reply can be sent. It is configured by the sender himself.
This is a special header that contains information about the sender and the location of the public DKIM key needed for verification. This header is required for all mail providers using DKIM, including Gmail, Yandex and Mail.ru!
v: version (always 1)
a: algorithms used for encryption
c: algorithms used for canonicalization
s: DKIM key selector name
bh: Message body hash
h: signed header fields that are used to generate the hash
b: DKIM hash or signature
The MIME-Version header indicates that the email is in MIME format.
Priority. Set by the email sender to tell the mail service that it intends to start a bulk mail.
Headers starting with X are generated by Google's SMTP server. Here we can find out the IP address and SMTP ID of the receiving mail server, as well as the date and time the email was received.
This is a DMARC specification that helps preserve email authentication results and checks for intermediaries between sender and recipient.
This header checks again if the authentication passed or failed. If yes, it will show the result.