SMTP errors - Inbox Help

Vispārīgs apraksts: General description: For some reasons, at present moment receiving server cannot receive the mail but the next attempt to send the mail might be successful. Try again later!

Example	Description
451 4.3.0 <user@domain.xx>: Temporary lookup failure; …	Technical problem at incoming inbox.lv servers. In case of these problems, please, contact our support team by email support@inbox.lv
Connection refused	Technical problem at receiving servers. Receiving server does not receive incoming messages. Please inform to your receiving servers (example, mobile operator or other) about this problem.

General description: Server cannot get access to the mailbox for mail delivery. It can be caused by damage of the mailbox or the mailbox can be at different server which is unavailable at the moment.

Also network connection may have been disconnected during sending or distant mail server does not want to receive mail from your server for some reasons. Repeated attempt to send mail to this mailbox can be successful.

Example	Description
450 4.1.8 <sender@domain.xx>: Sender address rejected: Domain not found; ….	Our inbound SMTP servers require that the domain name of the sender's email has valid MX or A records in order to accept the email. You may send emails from addresses that can be replied back only.
450 4.7.1 Client host rejected: cannot find your hostname, ….	Our inbound servers require reverse hostname for the sender server to be present in order to accept the email. You need to contact the reverse hostname's email admin to add the DNS into his server.
450 4.1.8 <sender@domain.tld>: Sender address rejected: Malformed DNS server reply; ….	Our inbound servers require that the hostname for the sender server should have valid MX or A records in order to accept emails from it. You need to contact the sending server's email admin to add valid DNS records for his server.
450 4.7.1 <www>: Helo command rejected: Host not found; …	Our inbound SMTP,servers require hostname provided in HELO to be present and be valid DNS name,in order to accept the email.

General description: Unacceptable e-mail address or domain name of mail address.

Example	Description
501 5.5.2 <host.?none?>: Helo command rejected: Invalid name;	Our inbound SMTP servers require hostname provided in HELO to be present and be valid DNS name in order to accept the email.

General description:: Repeating error 503 can indicate connection problems. Response 503 of SMTP most often indicates that SMTP server demands authentication and you are trying to send mail without authentication (login + password). Please check general settings to make sure that the settings of SMTP server are correct.

Example	Description
503 5.5.0 <domain.tld[xx.xx.xx.xx]>: Client host rejected: Improper use of SMTP command pipelining; ….	Sending server violates SMTP protocol as described in RFC 5321.
… Client host rejected: In order to send mail, please, login first (in reply to RCPT TO command)

General description: Size of mail (message + all its attachments) exceeds size limits of the recipient’s server. Please check the size of mail that you have prepared for sending, in particular, size of attachments. Probably, you will have to divide the mail into several parts.

Example	Description
552 5.3.4 Message size exceeds fixed limit; …..
552 5.3.4 The server of recipient returned the error: <xxx@xxx.xx>: message size 70756380 exceeds size limit 62914560 of server ….

General description: Sometimes error 550 can be sent by anti spam filter if user or domain to which you send mail or from which you receive mail has an established rule that prohibits mail sent by you. Also this error can indicate wrong address of the subscriber.

Also if this error appears, You can receive message about the undelivered email that appear to originate from your email address. In addition the name of your computer or provider mentioned in such message is wrong.

Example (Undelivered Mail Returned to Sender)	Description
Your message could not be delivered to one or more recipients. The server of recipient returned the error: <xxxx@xxx.xxx>: host mailin-04.mx.aol.com[xx.xx.xx.xxx] said: 550 5.1.1 <xxxx@xxx.xxx>: Recipient address rejected: aol.com (in reply to RCPT TO command)	Your email account has probably been compromised. Please change a password for your email and also change answer to the secret question. More

General description: Response 554 of SMTP server is returned by anti spam filter if there is a problem with e-mail address of the sender or IP address of the sender, or mailbox of the sender is listed in RBL. You have to either ask to add sender into the white list or you have to take measures in order to delete your IP address or ISP server from RBL (Realtime Blackhole List) Also response 554 of SMTP server means that e-mail address of the recipient is absent at the server. Contact the recipient for updating the e-mail address.

Wrong address
Example	Description
554 5.7.1 <user@xxx.xx>: Recipient address rejected: Inactive user; …….	Inactive user - automatically blocked account which has not been used for more than 9 months
554 5.7.1 <user@xxx.xx>: Recipient address rejected: Non existent user -user@xxx.xx (in reply to RCPT TO command)	Can not find user - there is no such user or mailbox was deleted
554 5.7.1 <user@xxx.xx>: Recipient address rejected: User unknown - user@xxx.xx;
IP address of the sender is listed in RBL
554 5.7.1 Service unavailable; Client host [xx.xx.xx.xx] blocked using RBL; http://www.spamhaus.org/querybl?ip=xx.xx.xx.xx; …	This is the error message that is received of the IP address of the sender is listed at zen.spamhaus.org For further details, please check http://www.spamhaus.org/zen,OR check http://www.spamhaus.org/query/bl?ip and contact zen.spamhaus.org to get the IP De-listed.
554 5.7.1 <sender@domain.tld>: Relay access denied; ….
554 5.7.1 <sender@default.com>: Sender address rejected: blacklisted; ….
554 5.7.1 <unknown[xx.xx.xx.xx]>: Client host rejected: LTC-HOME - use apollo servers to send mails; ….
554 5.7.1 <hotmail.com>: Helo command rejected: Bad HELO, contact abuse@inbox.lv; …..
554 5.7.1 <alabama.usa.com>: Helo command rejected: Fake mail.com, contact abuse@inbox.lv;,…
Violations in SMTP protocol
554 5.7.1 <xx-xx-xx-xx.domain.tld>: Helo command rejected: ...	Message itself states that the IP address of sending server belongs to network pool used for end-users. Please use SMTP server of your mail provider to send out emails. In case of errors please use link from the bounce message from self-service.
554 5.7.1 <pool-xx.xx.xx.domain.tld[xx.xx.xx.xx]>: Client host rejected: Dynamic IP detected, visit http://help.inbox.lv/abuse/dynip (1); ...	You are here because our spam filters have detected that your mail server is located on dynamic DSL IP or dial-up and thus is probable source of spam. If that's not the case, you can submit this form, and IP address of your mail server will be unblocked. Please, visit http://help.inbox.lv/abuse/dynip to register your IP.

General description: One of servers on the path to destination server has a problem with DNS records settings. Contact admin of the sending server.

Example	Description
504 5.5.2 <localhost>: Helo command rejected: need fully-qualified hostname; …	This error often occurs when hostname specified in HELO command by sending server is not fully qualified domain name. i.e. it may need to be SMTP.YOURHOST.COM or something like that.
504 5.5.2 <sender>: Sender address rejected: need fully-qualified address; …	This diagnostic indicates the email address of a sender is not valid in part of domain name.