You could set up a relay proxy for SMTP running on a high port that connects to your customers SMTP server and connect to that.
T On Friday, October 6, 2017 at 9:05:36 PM UTC+8, Karl Tinawi wrote: > > Hi George/all, > > We're a small startup and we've invested in Google Cloud infrastructure > for hosting our platform. We offer a B2B service and it is imperative for > our customers to send emails to their clients using our platform (thus > using their SMTP). > > We're at a critical juncture in our early days and this is a showstopper > for us. Our users need to be able to send emails from their mail servers > using SMTP, whether it be Gmail, Yahoo, FastMail, or whoever. Using > SendGrid or MailGun doesn't allow us to fulfil this requirement. > > There was a post from Paul Nash, here: > > https://googlecloudplatform.uservoice.com/forums/302595-compute-engine/suggestions/10079937-send-and-receive-email-using-tcp-smtp-imap-ports > that suggested that we could request SMTP and IMAP ports to be unblocked? > > I'd be very grateful for any advice as I'm currently looking at all > possible alternatives as we need to go live with this pretty soon. > > Thank you kindly, > Karl > > On Tuesday, August 8, 2017 at 3:12:20 PM UTC+1, George (Cloud Platform > Support) wrote: >> >> Google Compute Engine does not allow outbound connections on ports 25, >> 465, and 587. By default, these outbound SMTP ports are blocked because of >> the large amount of abuse these ports are susceptible to. You can find more >> information on how to send email from a VM and what services to use on the >> "Sending Email from an Instance" documentation page >> <https://cloud.google.com/compute/docs/tutorials/sending-mail/>. >> > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/6aec80ee-e6a6-4a60-9168-b8cc840aabfa%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
