Pros mailman-owner\

[Christos Ricudis]

Hello DJ!

 >> Exoun perasei tosa xronia ki akoma na katalabw giati oi
 >> an8rwpoi epimenoyn na stelnoyn ta mails toys apo to Unix box 
 >> toys se ena SMTP relay poy 8a kanei akribws thn idia douleia 
 >> poy mporei na kanei hdh to Unix tous.

 DA> Υποννοείς να ρυθμίσει κάποιος το sendmail ώστε να κάνει
 DA> Masquerade host?? (μιλάμε για dialup, δεν έχουμε DNS entry, 
 DA> άρα οι hosts των recipients, θα απαντάνε "cannot route to 
 DA> sender" αν πάς να το στείλεις έτσι ...)

Sygnwmmh, se wdeio ema8es Internet? 

1) Elaxista dialups den exoyn "dns entry", kai logika anhkoyn se ISPs poy
8a'prepe na kleisoun to magazi kai na kanoyn kati poy kseroyn kalytera. 

2) Akoma kai s'ayth thn periptwsh, to an "exoume DNS entry" einai asxeto. Mail
mporeis na steileis PANTOU [1]. 

3) Ti einai to "cannot route to sender"? Prwth fora blepw tetoio error. 

4) To masquerade-as einai asxeto me thn olh istoria. 

Profanws mperdeyeis to mail header me to SMTP envelope kai to TCP connection
information. Enas mail server: 

a) Dexetai TCP connections apo pantou, kai pairnei mail apo olous, eite eisai
"SMTP relay" eite eisai dialup user den exei shmasia. 

b) Koitazei to SMTP envelope information poy toy stelneis sto SMTP session, kai
EKEI koitazei an to domain sto SMTP envelope einai resolvable. Profanws kai
einai, mia kai sto pine sou logou xarh exeis dhlwsei san domain to
"mydomain.gr", kai oxi to "ppp1243.ispoulas.gr". 

c) Koitazei an epitrepetai to relaying basei toy sygkekrimenou envelope
information poy tou exeis dwsei. Profanws kai epitrepetai, mia poy eisai
syndedemenos se kapoio MX host gia to domain sto opoio apey8ynetai to mail. 

d) ENDEXETAI NA koitazei an to domain information ston mail header (poy einai
ASXETO me to SMTP envelope information, asxetws an synh8ws sympiptei) anhkei
pragmati se kapoion. Profanws kai anhkei, gia ton idio logo me to b. 

 DA> Αλλά και πάλι, το smart relay host δεν είναι καλύτερη λύση ??
 DA> Στην από πάνω περίπτωση, αν κάτι έχει γίνει και οι mail servers των
 DA> recipients είναι down, θα πρέπει να μείνεις online μέχρι το mail 
 DA> τελικά να φτάσει στον προορισμό του ....

Etsi ki alliws to mail 8a prepei na perimenei kai na ginetai requeue, to mono
poy se glytwnei enas monimws syndedemenos sto diktyo SMTP relay einai oti to
mail sou endexetai na ftasei kapws nwritera ston proorismo toy, mia kai ta
requeueings einai ek twn pragmatwn syxnotera. (sthn pragmatikothta spaniws
xreiasthke na kanw kati tetoio). 

[1] H eksairesh einai orismenoi ISP's poy kanoyn block ta outgoing SMTP
connections apo ta dialup blocks toys. Ekei PREPEI na xrhsimopoihseis SMTP
relay, an kai de nomizw na to kanei kanenas edw gyrw. 

--
Christos Ricudis

If god us wanted to RPN use, he would us made this way talk